Learn about the medical, dental, pharmacy, behavioral, and voluntary benefits your employer may offer.
Dramatic improvements in survival have been achieved for children and adolescents with cancer. Between 1975 and 2020, childhood cancer mortality decreased by more than 50%.[
Rhabdomyosarcoma, a tumor of striated muscle, is the most common soft tissue sarcoma in children aged 0 to 14 years and accounts for approximately 50% of tumors in this age group.[
NRSTS are often classified according to the normal tissue types from which they are derived. These types include various connective tissues, peripheral nervous system tissue, smooth muscle tissue, and vascular tissue. The classification also includes undifferentiated tumors that are not clearly related to specific tissue types. For more information about vascular tumors in children, see Childhood Vascular Tumors Treatment.
Distribution of Soft Tissue Sarcoma by Age and Histology
Pediatric soft tissue sarcomas are a heterogenous group of malignant tumors that originate from primitive mesenchymal tissue and account for 6% of all childhood tumors (rhabdomyosarcomas, 3%; other soft tissue sarcomas, 3%).[
The World Health Organization (WHO) published a revision to their classification of soft tissue and bone tumors in 2020. The classification had several updates to existing classification, nomenclature, grading, and risk stratification schemes. Notably, the revised classification includes newly described entities, and it uses molecular alterations in the classifications.[
The distribution of soft tissue sarcomas by histology and age, on the basis of the Surveillance, Epidemiology, and End Results (SEER) Program information from 2000 to 2015, is depicted in Table 1. The distribution of histological subtypes by age is also shown in Figure 2.
| Age <5 y | Age 5–9 y | Age 10–14 y | Age 15–19 y | Age <20 y | All Ages (Including Adults) | ||
---|---|---|---|---|---|---|---|---|
pPNET = peripheral primitive neuroectodermal tumors; SEER = Surveillance, Epidemiology, and End Results. | ||||||||
a Source: SEER database.[ |
||||||||
All soft tissue and other extraosseous sarcomas | 1,124 | 773 | 1,201 | 1,558 | 4,656 | 80,269 | ||
Rhabdomyosarcomas | 668 | 417 | 382 | 327 | 1,794 | 3,284 | ||
Fibrosarcomas, peripheral nerve, and other fibrous neoplasms | 137 | 64 | 112 | 181 | 494 | 6,645 | ||
Fibroblastic and myofibroblastic tumors | 114 | 33 | 41 | 77 | 265 | 4,228 | ||
Nerve sheath tumors | 23 | 31 | 70 | 102 | 226 | 2,303 | ||
Other fibromatous neoplasms | 0 | 0 | 1 | 2 | 3 | 114 | ||
Kaposi sarcoma | 2 | 1 | 2 | 10 | 15 | 7,722 | ||
Other specified soft tissue sarcomas | 237 | 238 | 559 | 865 | 1,899 | 49,004 | ||
Ewing tumor and Askin tumor of soft tissue | 37 | 36 | 72 | 113 | 258 | 596 | ||
pPNET of soft tissue | 24 | 23 | 42 | 56 | 145 | 402 | ||
Extrarenal rhabdoid tumor | 75 | 8 | 9 | 4 | 96 | 205 | ||
Liposarcomas | 4 | 6 | 37 | 79 | 126 | 10,749 | ||
Fibrohistiocytic tumors | 43 | 73 | 142 | 223 | 481 | 13,531 | ||
Leiomyosarcomas | 11 | 14 | 19 | 41 | 85 | 14,107 | ||
Synovial sarcomas | 12 | 39 | 141 | 210 | 402 | 2,608 | ||
Blood vessel tumors | 12 | 9 | 11 | 32 | 64 | 4,238 | ||
Osseous and chondromatous neoplasms of soft tissue | 1 | 6 | 16 | 14 | 37 | 1,018 | ||
Alveolar soft parts sarcoma | 4 | 5 | 22 | 33 | 64 | 211 | ||
Miscellaneous soft tissue sarcomas | 14 | 19 | 48 | 60 | 141 | 1,339 | ||
Unspecified soft tissue sarcomas | 80 | 53 | 146 | 175 | 454 | 13,614 |
NRSTS are more common in adolescents and adults.[
Figure 1. The distribution of nonrhabdomyosarcomatous soft tissue sarcomas by age according to stage.
Figure 2. The distribution of nonrhabdomyosarcomatous soft tissue sarcomas by age according to histological subtype.
Figure 3. The distribution of nonrhabdomyosarcomatous soft tissue sarcomas by age according to tumor site.
Risk Factors
Some genetic factors and external exposures have been associated with the development of NRSTS, including the following:
Clinical Presentation
Although NRSTS can develop in any part of the body, they arise most commonly in the trunk and extremities.[
Systemic symptoms (e.g., fever, weight loss, and night sweats) are rare. Hypoglycemia and hypophosphatemic rickets have been reported in cases of hemangiopericytoma (now identified as a solitary fibrous tumor in the revised World Health Organization classification system), whereas hyperglycemia has been noted in patients with fibrosarcoma of the lung.[
Diagnostic and Staging Evaluation
When a suspicious lesion is identified, it is crucial that a complete workup, followed by adequate biopsy be performed. The lesion is imaged before initiating any intervention using the following procedures:
In a prospective study of pediatric patients with sarcoma who underwent sentinel lymph node biopsy, 28 patients were examined. Sentinel lymph node biopsy was positive in 7 of the 28 patients, including 3 patients who had negative PET-CT scans. The findings from the sentinel lymph node biopsies resulted in altering therapy in all 7 patients in whom metastatic disease was determined by sentinel lymph node biopsy. In addition, three of the seven patients with proven malignant sentinel nodes (43%) had cross-sectional and functional imaging (PET) that were negative. PET-CT overestimated and suggested nodal involvement in more patients than what was confirmed by sentinel lymph node biopsy. As indicated by previous reports, epithelioid sarcoma and clear cell sarcoma were the two nonrhabdomyosarcomatous tumors included in this study.[
The imaging characteristics of some tumors can be highly suggestive of that particular diagnosis. For example, the imaging characteristics of pediatric low-grade fibromyxoid sarcoma and alveolar soft part sarcoma have been described and can aid in the diagnosis of these rare neoplasms.[
Biopsy strategies
Although NRSTS are pathologically distinct from rhabdomyosarcoma and Ewing sarcoma, the classification of childhood NRSTS type is often difficult. Core-needle biopsy, incisional biopsy, or excisional biopsy can be used to diagnose a NRSTS. If possible, the surgeon who will perform the definitive resection needs to be involved in the biopsy decision. Poorly placed incisional or needle biopsies may adversely affect the ability to achieve negative margins.
Given the diagnostic importance of translocations and other molecular changes, a core-needle biopsy or small incisional biopsy that obtains adequate tumor tissue is crucial to allow for conventional histology, immunocytochemical analysis, and other studies such as light and electron microscopy, cytogenetics, fluorescence in situ hybridization, and molecular pathology.[
For these reasons, open biopsy or multiple core-needle biopsies are strongly encouraged so that adequate tumor tissue can be obtained to allow crucial studies to be performed and to avoid limiting future treatment options.
Unplanned resection
In children with unplanned resection of NRSTS, primary re-excision is frequently recommended because many patients will have tumor present in the re-excision specimen.[
Chromosomal abnormalities
Many NRSTS are characterized by chromosomal abnormalities. Some of these chromosomal translocations lead to a fusion of two disparate genes. The resulting fusion transcript can be readily detected by using polymerase chain reaction–based techniques, thus facilitating the diagnosis of those neoplasms that have translocations.
Some of the most frequent aberrations seen in NRSTS are listed in Table 2.
Histology | Chromosomal Aberrations | Genes Involved |
---|---|---|
a Adapted from Sandberg,[ |
||
Alveolar soft part sarcoma | t(x;17)(p11.2;q25) | ASPSCR1::TFE3[ |
Angiomatoid fibrous histiocytoma | t(12;16)(q13;p11), t(2;22)(q33;q12), t(12;22)(q13;q12) | FUS::ATF1,EWSR1::CREB1,[ |
BCOR-rearranged sarcomas | inv(X)(p11.4;p11.2) | BCOR::CCNB3 |
CIC-rearranged sarcomas | t(4;19)(q35;q13), t(10;19)(q26;q13) | CIC::DUX4 |
Clear cell sarcoma | t(12;22)(q13;q12), t(2;22)(q33;q12) | EWSR::ATF11,EWSR1::CREB1[ |
Congenital (infantile) fibrosarcoma/mesoblastic nephroma | t(12;15)(p13;q25) | ETV6::NTRK3 |
Dermatofibrosarcoma protuberans | t(17;22)(q22;q13) | COL1A1::PDGFB |
Desmoid fibromatosis | Trisomy 8 or 20, loss of 5q21 | CTNNB1orAPCmutations |
Desmoplastic small round cell tumors | t(11;22)(p13;q12) | EWSR1::WT1[ |
Epithelioid hemangioendothelioma | t(1;3)(p36;q25)[ |
WWTR1::CAMTA1 |
Epithelioid sarcoma | Inactivation ofSMARCB1 | SMARCB1 |
Extraskeletal myxoid chondrosarcoma | t(9;22)(q22;q12), t(9;17)(q22;q11), t(9;15)(q22;q21), t(3;9)(q11;q22) | EWSR1::NR4A3,TAF2N::NR4A3,TCF12::NR4A3,TFG::NR4A3 |
Hemangiopericytoma | t(12;19)(q13;q13.3) and t(13;22)(q22;q13.3) | LMNA::NTRK1[ |
Infantile fibrosarcoma | t(12;15)(p13;q25) | ETV6::NTRK3 |
Inflammatory myofibroblastic tumor | t(1;2)(q23;q23), t(2;19)(q23;q13), t(2;17)(q23;q23), t(2;2)(p23;q13), t(2;11)(p23;p15)[ |
TPM3::ALK,TPM4::ALK,CLTC::ALK,RANBP2::ALK,CARS1::ALK,RAS |
Infantile myofibromatosis | Gain-of-function mutations | PDGFRB[ |
Low-grade fibromyxoid sarcoma | t(7;16)(q33;p11), t(11;16)(p11;p11) | FUS::CREB3L2,FUS::CREB3L1 |
Malignant peripheral nerve sheath tumor | 17q11.2, loss or rearrangement of 10p, 11q, 17q, 22q | NF1 |
Mesenchymal chondrosarcoma | Del(8)(q13.3q21.1) | HEY1::NCOA2 |
Myoepithelioma | t(19;22)(q13;q12), t(1;22)(q23;q12), t(6;22)(p21;q12) | EWSR1::ZNF44,EWSR1::PBX1,EWSR1::POU5F1 |
Myxoid/round cell liposarcoma | t(12;16)(q13;p11), t(12;22)(q13;q12) | FUS::DDIT3,EWSR1::DDIT3 |
Primitive myxoid mesenchymal tumor of infancy | Internal tandem duplication | BCOR |
Rhabdoid tumor | Inactivation ofSMARCB1 | SMARCB1 |
Sclerosing epithelioid fibrosarcoma | t(11;22)(p11;q12), t(19;22)(p13;q12) | EWSR1::CREB3L1,EWSR1::CREB3L3 |
Solitary fibrous tumor | inv(12)(q13q13) | NAB2::STAT6 |
Synovial sarcoma | t(x;18)(p11.2;q11.2) | SS18::SSX |
Tenosynovial giant cell tumor | t(1;2)(p13;q35) | COL6A3::CSF1 |
Prognosis and Prognostic Factors
The prognosis of NRSTS varies greatly depending on the following factors:[
In a review of a large adult series of NRSTS, patients with superficial extremity sarcomas had a better prognosis than did patients with deep tumors. Thus, in addition to grade and size, the depth of invasion of the tumor should be considered.[
Several adult and pediatric series have shown that patients with large or invasive tumors have a significantly worse prognosis than do those with small, noninvasive tumors. A retrospective review of soft tissue sarcomas in children and adolescents suggests that the 5 cm cutoff used for adults with soft tissue sarcoma may not be ideal for smaller children, especially infants. The review identified an interaction between tumor diameter and body surface area.[
Some pediatric NRSTS are associated with a better outcome. For instance, patients with infantile fibrosarcoma who present in infancy and younger than 5 years have an excellent prognosis. This excellent outcome occurs because surgery alone can cure a significant number of these patients, the tumor is highly chemosensitive, and the tumor responds well to larotrectinib, a specific tropomyosin receptor kinase inhibitor.[
Soft tissue sarcomas in older children and adolescents often behave similarly to those in adult patients.[
Figure 4. Risk group and treatment assignment for the Children's Oncology Group ARST0332 trial. Reprinted from The Lancet Oncology, Volume 21 (Issue 1), Spunt SL, Million L, Chi YY, et al., A risk-based treatment strategy for non-rhabdomyosarcoma soft-tissue sarcomas in patients younger than 30 years (ARST0332): a Children's Oncology Group prospective study, Pages 145–161, Copyright © 2020, with permission from Elsevier.
Each patient was assigned to one of three risk groups and one of four treatment groups. The risk groups were as follows:[
The treatment groups were as follows:
Chemotherapy included six cycles of ifosfamide (3 g/m2 per dose) administered intravenously on days 1 through 3 and five cycles of doxorubicin (37.5 mg/m2 per dose) administered intravenously on days 1 to 2 every 3 weeks, with the sequence adjusted on the basis of the timing of surgery or radiation therapy.
For the 550 patients enrolled, 529 evaluable patients were included in the analysis; the survival results are shown in Table 3.
| 5-Year Event-Free Survival | 5-Year Overall Survival | ||
---|---|---|---|---|
Risk Group | Events/Patients | Estimate (%) | Events/Patients | Estimate (%) |
Low | 26/222 | 88.9 (84.0–93.8) | 10/222 | 96.2 (93.2–99.2) |
Intermediate | 84/227 | 65.0 (58.2–71.8) | 55/227 | 79.2 (73.4–85.0) |
High | 63/80 | 21.2 (11.4–31.1) | 52/80 | 35.5 (23.6–47.4) |
Pediatric patients with unresected localized NRSTS have a poor outcome. Only about one-third of patients treated with multimodality therapy remain disease free.[
The European Pediatric Soft Tissue Sarcoma Study Group (EpSSG) conducted a prospective trial for patients younger than 21 years with NRSTS. They reported an analysis of 206 patients with synovial sarcoma and 363 with adult-type NRSTS. Treatment was administered after assignment of patients to risk groups (see Figure 5).[
Figure 5. Treatment plan for patients with synovial sarcoma or adult-type non-rhabdomyosarcoma soft tissue sarcomas. Patients were divided into four treatment groups based on surgical stage, tumour size, nodal involvement, tumour grade (according to the Fédération Nationale des Centres de Lutte Contre le Cancer grading system for adult-type non-rhabdomyosarcoma soft tissue sarcomas), and tumour site (for synovial sarcoma). I+D = ifosfamide (3.0 g/m2 per day intravenously for 3 days) plus doxorubicin (37.5 mg/m2 intravenously per day for 2 days). I = ifosfamide (3.0 g/m2 intravenously per day for 2 days). IRS = Intergroup Rhabdomyosarcoma Study. N1 = nodal involvement. S = delayed surgery. Reprinted from The Lancet Child & Adolescent Health, Volume 5, Issue 8, Ferrari A, van Noesel MM, Brennan B, et al., Paediatric non-rhabdomyosarcoma soft tissue sarcomas: the prospective NRSTS 2005 study by the European Pediatric Soft Tissue Sarcoma Study Group (EpSSG), Pages 546-558, Copyright 2021, with permission from Elsevier.
Treatment Group | 5-Year Event-Free Survival Rate (95% CI) | 5-Year Overall Survival Rate (95% CI) | Local Recurrence Rate |
---|---|---|---|
CI = confidence interval; EpSSG = European Pediatric Soft Tissue Sarcoma Study Group; NRSTS = nonrhabdomyosarcomatous soft tissue sarcomas. | |||
Surgery alone | 91.4% (87.0%–94.4%) | 98.1% (95.0%–99.3%) | |
Adjuvant radiation therapy alone | 75.5% (46.9%–90.1%) | 88.2% (60.6%–96.9%) | 6.7% (1/15) |
Adjuvant chemotherapy ± radiation therapy | 65.6% (54.8%–74.5%) | 75.8% (65.3%–83.5%) | 10.8% (7/65) |
Neoadjuvant chemotherapy ± radiation therapy | 56.4% (49.3%–63.0%) | 70.4% (63.3%–76.4%) | 14.2% (16/113) |
The authors concluded that adjuvant therapy could safely be omitted in the group of patients assigned to surgery alone. They also concluded that improving the outcome for patients with high-risk, initially resected, adult-type NRSTS and those with initially unresected disease remains a major clinical challenge.[
In a pooled analysis from U.S. and European pediatric centers, outcome was better for patients whose tumor removal procedure was deemed complete than for patients whose tumor removal was incomplete. Outcome was better for patients who received radiation therapy than for patients who did not.[
Because long-term morbidity must be minimized while disease-free survival is maximized, the ideal therapy for each patient must be carefully and individually determined using these prognostic factors before initiating therapy.[
Related Summaries
For information about other types of sarcoma, see the following summaries:
References:
World Health Organization (WHO) Classification of Soft Tissue Tumors
The WHO classification system for cancer represents the common nomenclature for cancer worldwide. In the United States, it has been adopted by the American Joint Committee on Cancer (AJCC) for sarcoma staging and the College of American Pathologists (CAP) cancer protocols for bone and soft tissue sarcomas. The fifth edition of the WHO Classification of Soft Tissue and Bone Tumors was published in 2020.[
The grading of soft tissue tumors has always been a controversial issue. The 2020 WHO classification represents the consensus of several soft tissue pathologists and geneticists, as well as a medical oncologist, radiologist, and surgeon. This edition further integrates morphology and genetic information into the classification. For example, a new category of tumors called NTRK-rearranged spindle cell neoplasms was included, but infantile fibrosarcoma was excluded from this group. This classification also defined the undifferentiated small cell sarcomas of bone and soft tissue by separating Ewing sarcoma from entities such as CIC-rearranged sarcomas, BCOR-rearranged sarcomas, and EWSR1 gene fusions involving non-ETS partner genes. Ewing sarcoma is now in the same area rather than in the bone tumor section to reflect the variable presentation sites and the variety of translocations associated with this entity.[
Angioleiomyoma was reclassified under perivascular tumors.
With the increased use of next-generation sequencing techniques and heightened awareness of recently approved tyrosine kinase inhibitors that target NTRK and other genes, newer subgroups of pediatric soft tissue lesions that are characterized by kinase fusions have been identified and share a similar morphological spectrum. It is important to identify these rare entities because some of them might be amenable to therapeutic targeting with novel agents. Some examples of these lesions are described below.[
References:
Clinical staging has an important role in predicting the clinical outcome and determining the most effective therapy for pediatric soft tissue sarcomas. As yet, there is no well-accepted staging system that is applicable to all childhood sarcomas. The system from the American Joint Committee on Cancer (AJCC) that is used for adults has not been validated in pediatric studies.
Although a standardized staging system for pediatric nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS) does not exist, two systems are currently in use for staging pediatric NRSTS:[
Intergroup Rhabdomyosarcoma Study Staging System
Nonmetastatic disease
Metastatic disease
Recurrent/progressive disease
TNM Staging System
The eighth edition of the AJCC Cancer Staging Manual has designated staging by the four criteria of tumor size, nodal status, histologic grade, and metastasis and by anatomic primary tumor site (head and neck; trunk and extremities; abdomen and thoracic visceral organs; retroperitoneum; and unusual histologies and sites) (see Tables 5, 6, 7, and 8).[
T Category | Soft Tissue Sarcoma of the Trunk, Extremities, and Retroperitoneum | Soft Tissue Sarcoma of the Head and Neck | Soft Tissue Sarcoma of the Abdomen and Thoracic Visceral Organs |
---|---|---|---|
a Adapted from O'Sullivan et al.,[ |
|||
TX | Primary tumor cannot be assessed. | Primary tumor cannot be assessed. | Primary tumor cannot be assessed. |
T0 | No evidence of primary tumor. | ||
T1 | Tumor ≤5 cm in greatest dimension. | Tumor ≤2 cm. | Organ confined. |
T2 | Tumor >5 cm and ≤10 cm in greatest dimension. | Tumor >2 to ≤4 cm. | Tumor extension into tissue beyond organ. |
T2a | Invades serosa or visceral peritoneum. | ||
T2b | Extension beyond serosa (mesentery). | ||
T3 | Tumor >10 cm and ≤15 cm in greatest dimension. | Tumor >4 cm. | Invades another organ. |
T4 | Tumor >15 cm in greatest dimension. | Tumor with invasion of adjoining structures. | Multifocal involvement. |
T4a | Tumor with orbital invasion, skull base/dural invasion, invasion of central compartment viscera, involvement of facial skeleton, or invasion of pterygoid muscles. | Multifocal (2 sites). | |
T4b | Tumor with brain parenchymal invasion, carotid artery encasement, prevertebral muscle invasion, or central nervous system involvement via perineural spread. | Multifocal (3–5 sites). | |
T4c | Multifocal (>5 sites). |
a Adapted from O'Sullivan et al.,[ |
|
b For soft tissue sarcoma of the abdomen and thoracic visceral organs, N0 = no lymph node involvement or unknown lymph node status and N1 = lymph node involvement present. | |
N0 | No regional lymph node metastasis or unknown lymph node status.b |
N1 | Regional lymph node metastasis.b |
a Adapted from O'Sullivan et al.,[ |
|
b For soft tissue sarcoma of the abdomen and thoracic visceral organs, M0 = no metastases and M1 = metastases present. | |
M0 | No distant metastasis.b |
M1 | Distant metastasis.b |
Stage | T | N | M | Grade |
---|---|---|---|---|
T = primary tumor; N = regional lymph node; M = distant metastasis. | ||||
a Adapted from Yoon et al.[ |
||||
b Stage IIIB for soft tissue sarcoma of the retroperitoneum; stage IV for soft tissue sarcoma of the trunk and extremities. | ||||
IA | T1 | N0 | M0 | G1, GX |
IB | T2, T3, T4 | N0 | M0 | G1, GX |
II | T1 | N0 | M0 | G2, G3 |
IIIA | T2 | N0 | M0 | G2, G3 |
IIIB | T3, T4 | N0 | M0 | G2, G3 |
IIIB/IVb | Any T | N1 | M0 | Any G |
IV | Any T | Any N | M1 | Any G |
Soft Tissue Sarcoma Tumor Pathological Grading System
In most cases, accurate histopathological classification alone of soft tissue sarcomas does not yield optimal information about their clinical behavior. Therefore, several histological parameters are evaluated in the grading process, including the following:
This process is used to improve the correlation between histological findings and clinical outcome.[
Testing the validity of a grading system within the pediatric population is difficult because of the rarity of these neoplasms. In March 1986, the Pediatric Oncology Group (POG) conducted a prospective study on pediatric soft tissue sarcomas other than rhabdomyosarcoma and devised the POG grading system. Analysis of outcome for patients with localized soft tissue sarcomas other than rhabdomyosarcoma demonstrated that patients with grade 3 tumors fared significantly worse than those with grade 1 or grade 2 lesions. This finding suggests that this system can accurately predict the clinical behavior of NRSTS.[
The grading systems developed by the POG and the French Federation of Comprehensive Cancer Centers (Fédération Nationale des Centres de Lutte Contre Le Cancer [FNCLCC]) Sarcoma Group are described below.
POG grading system
The POG grading system is described below.[
Grade I
Grade I lesions are based on histological type, well-differentiated cytohistological features, and/or age of the patient.
Grade II
Grade II lesions are soft tissue sarcomas not included in grade I or III by histological diagnosis (with <5 mitoses/10 high-power fields or <15% necrosis):
Grade III
Grade III lesions are similar to grade II lesions and include certain tumors known to be clinically aggressive by virtue of histological diagnosis and non-grade I tumors (with >4 mitoses per 10 high-power fields or >15% necrosis):
FNCLCC grading system
The FNCLCC histological grading system was developed for adults with soft tissue sarcoma. The purpose of the grading system is to predict which patients will develop metastasis and subsequently benefit from postoperative chemotherapy.[
FNCLCC = Fédération Nationale des Centres de Lutte Contre Le Cancer; HPF = high-power field. | |
Tumor Differentiation | |
Score 1 | Sarcoma closely resembling normal adult mesenchymal tissue (e.g., well-differentiated liposarcoma) |
Score 2 | Sarcomas for which histologic typing is certain (e.g., myxoid liposarcoma) |
Score 3 | Embryonal and undifferentiated sarcomas, sarcomas of doubtful type, and synovial sarcomas |
Mitotic Count | |
Score 1 | 0–9 mitoses per 10 HPF |
Score 2 | 10–19 mitoses per 10 HPF |
Score 3 | ≥20 mitoses per 10 HPF |
Tumor Necrosis | |
Score 0 | No necrosis |
Score 1 | <50% tumor necrosis |
Score 2 | ≥50% tumor necrosis |
Total Score | Histologic Grade |
---|---|
2–3 | Grade I |
4–5 | Grade II |
6–8 | Grade III |
Prognostic Significance of Tumor Grading
The POG and FNCLCC grading systems have proven to be of prognostic value in pediatric and adult NRSTS.[
The Children's Oncology Group (COG) ARST0332 (NCT00346164) trial compared the POG and FNCLCC pathologic grading systems as part of a prospective risk-based strategy. The study found that, in addition to tumor depth and invasiveness, the FNCLCC grade was strongly associated with event-free survival and overall survival.[
References:
Because of the rarity of pediatric nonrhabdomyosarcomatous soft tissue sarcomas (NRSTS), treatment should be coordinated by a multidisciplinary team that includes oncologists (pediatric or medical), pathologists, surgeons, and radiation oncologists for all children, adolescents, and young adults with these tumors. In addition, to better define the tumors' natural history and response to therapy, entry into national or institutional treatment protocols should be considered for children with rare neoplasms. Information about ongoing clinical trials is available from the NCI website.
The Children's Oncology Group (COG) performed a prospective nonrandomized trial (ARST0332 [NCT00346164]) for patients with soft tissue sarcomas.[
Surgical resection of the primary tumor was classified as follows:
Patients were assigned to one of the following three risk groups:
The treatment groups were as follows:
Chemotherapy included six cycles of intravenous (IV) ifosfamide (3 g/m2 per dose) on days 1 through 3 and five cycles of IV doxorubicin (37.5 mg/m2 per dose) on days 1 to 2 every 3 weeks, with the sequence adjusted on the basis of timing of surgery or radiation therapy.
The analysis included 529 evaluable patients: low risk (n = 222), intermediate risk (n = 227), and high risk (n = 80). Patients underwent surgery alone (n = 205), radiation therapy (n = 17), chemoradiation therapy (n = 111), and neoadjuvant chemoradiation therapy (n = 196).
At a median follow-up of 6.5 years (interquartile range [IQR], 4.9–7.9), the 5-year event-free survival (EFS) and overall survival (OS) rates, by risk group, were as follows:
The authors concluded that pretreatment clinical features can be used to effectively define treatment failure risk and stratify young patients with NRSTS for risk-adapted therapy. Most low-risk patients can be cured without adjuvant therapy, avoiding known long-term treatment complications. Survival remains suboptimal for intermediate-risk and high-risk patients, and novel therapies are needed for these patients.
Surgery
Surgical resection of the primary tumor is the predominant therapy for most NRSTS. In the COG ARST0332 (NCT00346164) study, approximately 37% of patients younger than 30 years were treated with surgery alone.[
After an appropriate biopsy and pathological diagnosis, every attempt is made to resect the primary tumor. Completeness of resection predicts outcome. In the COG ARST0332 study, complete resections with negative microscopic margins (R0) resulted in the best outcomes, with 5-year EFS rates of 84%. Resection with positive microscopic margins (R1) led to an EFS rate of 66%. Resection with gross residual disease (R2) led to an EFS rate of 49%. The 5-year OS rates were 93% for R0, 80% for R1, and 63% for R2 resections.[
The timing of surgery depends on an assessment of the feasibility and morbidity of surgery. In the COG ARST0332 study, the outcomes were nearly identical for intermediate-risk patients who achieved an R0 or R1 resection with up-front surgery or surgery after neoadjuvant chemoradiation therapy (70% vs. 71%, respectively). An R0 resection was more likely to occur after neoadjuvant therapy.[
If the initial operation fails to achieve pathologically negative tissue margins or if the initial surgery was done without the knowledge that cancer was present, a re-excision of the affected area is performed to obtain clear, but not necessarily wide, margins.[
Regional lymph node metastases at diagnosis are unusual and are most often seen in patients with epithelioid and clear cell sarcomas.[
Radiation Therapy
Considerations for radiation therapy are based on the potential for surgery, with or without chemotherapy, to obtain local control without loss of critical organs or significant functional, cosmetic, or psychological impairment. This will vary according to the following:
Radiation therapy can be given preoperatively or postoperatively. It can also be used as definitive therapy in rare situations in which surgical resection is not performed.[
Preoperative radiation therapy has been associated with excellent local control rates.[
Retroperitoneal sarcomas are unique in that radiosensitivity of the bowel to injury makes postoperative radiation therapy less desirable.[
Radiation therapy can also be given postoperatively. In general, radiation is indicated for patients with inadequate surgical margins and for larger, high-grade tumors.[
Brachytherapy and intraoperative radiation may be applicable in select situations.[
Radiation volume and dose depend on the patient, tumor, and surgical variables noted above, as well as the following:
Radiation doses are typically 45 Gy to 50 Gy preoperatively, with consideration for postoperative boost of 10 Gy to 20 Gy if resection margins are microscopically or grossly positive, or planned brachytherapy if the resection is predicted to be subtotal. In addition, even in the preoperative setting, an additional boost of radiation at a dose of 60 Gy can be considered for areas of the tumor predicted to be at risk of residual microscopic disease (e.g., areas of tumor adjacent to critical normal tissues) that cannot be resected with adequate margins. This can be accomplished with a simultaneously integrated boost dose (i.e., higher dose area within the larger lower dose volume) or administered with a small field of radiation after the initial volume is treated with a dose of 45 Gy to 50 Gy. It also must be acknowledged that data documenting the efficacy of a postoperative boost to areas with microscopically positive margins are lacking.[
Radiation margins are typically 2 cm to 4 cm longitudinally and encompass fascial planes axially.[
Chemotherapy
The role of postoperative chemotherapy remains unclear.[
Evidence (lack of clarity regarding postoperative chemotherapy):
Targeted Therapy
The use of angiogenesis and mammalian target of rapamycin (mTOR) inhibitors has been explored in the treatment of adult soft tissue sarcomas but not in pediatrics.
Evidence (targeted therapy in adults with soft tissue sarcoma):
The COG and NRG Oncology cancer consortia conducted a randomized trial of pazopanib added to neoadjuvant chemotherapy (doxorubicin and ifosfamide) and preoperative radiation therapy in pediatric and adult patients with NRSTS. Patients whose tumors were larger than 5 cm and had intermediate- or high-grade disease were eligible. The end point of the trial was pathological tumor response after adjuvant therapy. Study entry was closed early because the planned interim analysis showed that the pathological response boundary was crossed. Eighty-one patients were enrolled, but only 42 (52%) were available for response data (17 patients from each group discontinued therapy for either progression, unacceptable toxicity, or patient or physician choice).[
References:
Cancer in children and adolescents is rare, although the overall incidence has been slowly increasing since 1975.[
For information about supportive care for children and adolescents with cancer, see the summaries on Supportive and Palliative Care.
The American Academy of Pediatrics has outlined guidelines for pediatric cancer centers and their role in the treatment of pediatric patients with cancer.[
Many therapeutic strategies for children and adolescents with soft tissue tumors are similar to those for adult patients, although there are important differences. For example, the biology of the neoplasm in pediatric patients may differ dramatically from that of the adult lesion. Additionally, limb-sparing procedures are more difficult to perform in pediatric patients. The morbidity associated with radiation therapy, particularly in infants and young children, may be much greater than that observed in adults.[
Improved outcomes with multimodality therapy in adults and children with soft tissue sarcomas over the past 20 years has caused increasing concern about the potential long-term side effects of this therapy in children, especially when considering the expected longer life span of children versus adults. Therefore, to maximize tumor control and minimize long-term morbidity, treatment must be individualized for children and adolescents with nonrhabdomyosarcomatous soft tissue sarcoma. These patients should be enrolled in prospective studies that accurately assess any potential complications.[
References:
Adipocytic Tumors
Adipocytic tumors account for less than 10% of soft tissue lesions in patients younger than 20 years. The most common adipocytic tumors in children are lipomas and lipoblastomas.
Table 11 summarizes the adipocytic neoplasms seen in pediatric patients and includes information about their corresponding clinico-pathological and molecular features.[
Adipocytic Tumors | Frequency[ |
Epidemiology | Predilection Site(s) | Histology | Cytogenetic/Molecular Alterations |
---|---|---|---|---|---|
M = male; F = female;HGMA2= high-mobility group AT-hook 2;PLAG1= pleomorphic adenoma gene 1;MDM2= mouse double minute 2 homolog;FUS= fused in sarcoma;DDIT3= DNA damage inducible transcript 3. | |||||
a Reprinted fromSeminars in Diagnostic Pathology, Volume 36, Issue 2, Putra J, Al-Ibraheemi A, Adipocytic tumors in Children: A contemporary review, Pages 95–104, Copyright 2019, with permission from Elsevier.[ |
|||||
Benign | |||||
Lipoma | 64%–70% (including variants) | • Solitary: M = F | Trunk. | Monotonous sheets of mature adipocytes. | Chromosomes 12q (HMGA2), 13q and 6p. |
• Multiple: M > F | |||||
• Uncommon in the first 2 decades of life. | |||||
• Most common seen between the age 40–60 years. | |||||
Angiolipoma | 4%–28% | • M > F | Trunk and extremities. | • Mature adipocytic proliferation. | — |
• Most common in late teens or early twenties. | • Vascular proliferation (capillary proliferation with fibrin thrombi). | ||||
Lipoblastoma | 18%–30% | • M > F | Trunk and extremities. | • Lobular architecture. | Chromosome 8q (PLAG1) rearrangement. |
• Zones of maturation. | |||||
• <3 years old (90%) | • Primitive stellate cells. | ||||
• Multivacuolated lipoblasts. | |||||
• Myxoid area with prominent plexiform vessels. | |||||
Hibernoma | 2% | • M = F | Back (scapular area), chest wall, axilla and inguinal regions. | • Lobular architecture. | Chromosome 11q13-21 rearrangement. |
• Rare in the first 2 decades of life (5%). | • Different type of cells: brown fat cells, multivacuolated lipoblasts, mature fat cells. | ||||
• 60% occur in the 3rd and 4th decades of life. | • Prominent capillary network (less pronounced than lipoblastoma and myxoid liposarcoma). | ||||
Intermediate | |||||
Atypical lipomatous tumor/well-differentiated liposarcoma | Rare | • M = F | Extremities, head and neck, trunk. | • Mature adipocytic proliferation. | Supernumerary ring and giant marker chromosome 12q14-15 (MDM2). |
• Extremely rare in children (associated with Li-Fraumeni syndrome). | • Significant variation in size. | ||||
• Peak incidence is 6th decade of life. | • Hyperchromatic nuclei with atypia. | ||||
Malignant | |||||
Myxoid liposarcoma | 4% | • F > M | Extremities, trunk, head and neck and abdominal regions. | • Nodular architecture. | Recurrent t(12;16)(q13;p11) resulting inFUS::DDIT3gene fusion. |
• Mixture of round to spindle nonlipogenic cells and lipoblasts. | |||||
• The most common liposarcoma in children (2nd decade of life), but less frequent than adults. | • Prominent myxoid stroma with chicken-wire vasculature. | ||||
• Variants seen in children: pleomorphic and spindle cell subtypes. | |||||
• Peak incidence is 4th and 5th decades of life. | • Progression to round cell morphology is uncommon in children. | ||||
Dedifferentiated liposarcoma | Rare | • Reported in an 8-year old with a well-differentiated liposarcoma.[ |
• Lower extremity in a single case report of pediatric patient.[ |
• Transition from a well-differentiated liposarcoma to nonlipogenic, high-grade sarcoma. | Supernumerary ring and giant marker chromosome 12q14-15 (MDM2). |
• Dedifferentiation occurs in up to 10% of well-differentiated liposarcomas in adults. | • Retroperitoneum (adults). | • Heterologous differentiation (5%–10%). | |||
• Peak incidence is 6th decade of life. | |||||
Pleomorphic liposarcoma | Rare/not reported | • Peak incidence of pleomorphic liposarcoma is 7th decade of life. | • Extremities (adults). | • Pleomorphic lipoblasts. | — |
• The subtype has been reported in the settings of Li-Fraumeni[ |
• Background of a high-grade, pleomorphic sarcoma (non-lipogenic). |
Liposarcoma, well-differentiated, not otherwise specified (NOS)
Liposarcoma accounts for 3% of soft tissue sarcoma in patients younger than 20 years (see Table 1).
Liposarcoma is rare in the pediatric population. In a review of 182 pediatric patients with adult-type sarcomas, only 14 had a diagnosis of liposarcoma.[
A literature review of 275 cases of pediatric liposarcoma showed that myxoid liposarcoma was the most common histology (68%), followed by well-differentiated liposarcoma (10.5%). Twelve percent of patients died of disease, and most of the deaths occurred in patients with the pleomorphic and myxoid pleomorphic subtypes. About 70% of patients with myxoid and well-differentiated liposarcoma were treated with surgery only. The overall clinical outcomes for these groups of patients were excellent, with no evidence of disease in 114 of 127 patients. In contrast, more than 50% of patients with pleomorphic liposarcoma received radiation therapy and chemotherapy in addition to surgery, and their clinical outcome was suboptimal, with no evidence of disease in only 5 of 10 patients. Germline TP53 mutations were seen in two patients with myxoid pleomorphic liposarcoma and two patients with well-differentiated liposarcoma who had a family history compatible with Li-Fraumeni syndrome.[
Histopathological classification
The World Health Organization (WHO) classification for liposarcoma is as follows:[
Clinical presentation
Most liposarcomas in the pediatric and adolescent age range are low grade and located subcutaneously. Metastasis to lymph nodes is uncommon, and most metastases are pulmonary. Tumors arising in the periphery are more likely to be low grade and myxoid. Tumors arising centrally are more likely to be high grade, pleomorphic, and present with metastasis or recur with metastasis.
Genomic characteristics
Prognosis
Higher grade or central tumors are associated with a significantly higher risk of death. In an international retrospective review, the 5-year survival rate was 42% for patients with central tumors. Seven of ten patients with pleomorphic myxoid liposarcoma died of their disease.[
Treatment
Treatment options for liposarcoma include the following:
Surgery is the most important treatment for liposarcoma. After complete surgical resection of well-differentiated or myxoid liposarcoma, the event-free survival (EFS) and overall survival (OS) rates are roughly 90%.[
Chemotherapy has been used to decrease the size of liposarcoma before surgery to facilitate complete resection, particularly in central tumors.[
Trabectedin has produced encouraging responses in adults with advanced myxoid liposarcoma.[
Treatment with eribulin, a nontaxane microtubule dynamics inhibitor, significantly improved survival in adult patients with recurrent liposarcoma compared with dacarbazine. The median OS was 15.6 months for patients who received eribulin, versus 8.4 months for patients who received dacarbazine. Survival differences were more pronounced in patients with dedifferentiated and pleomorphic liposarcoma. Eribulin was effective in prolonging survival of patients with either high-grade or intermediate-grade tumors.[
In a phase II, single-arm, multicenter study, 41 adult patients with unresectable or metastatic high-grade or intermediate-grade liposarcoma were treated with pazopanib at a dose of 800 mg daily. The progression-free survival (PFS) rate at 12 weeks was 68.3%, which was significantly greater than the null hypothesis value of 40%. Forty-four percent of patients experienced tumor control. One patient had a partial response, and 17 patients had stable disease. At 24 weeks, 39% of the patients remained progression free. The median progression-free survival was 4.4 months, and median OS was 12.6 months.[
Chondro-osseous Tumors
Chondro-osseous tumors have several subtypes, including the following:
Extraskeletal mesenchymal chondrosarcoma
Osseous and chondromatous neoplasms account for 0.8% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Histopathology and molecular features
Mesenchymal chondrosarcoma is a rare tumor characterized by small round cells and hyaline cartilage that more commonly affects young adults and has a predilection for involving the head and neck region.
Mesenchymal chondrosarcoma has been associated with consistent chromosomal rearrangement. A retrospective analysis of cases of mesenchymal chondrosarcoma identified a HEY1::NCOA2 fusion in 10 of 15 tested specimens.[
Prognosis
A retrospective survey of European institutions identified 113 children and adults with mesenchymal chondrosarcoma. Factors associated with better outcome included the following:[
A retrospective analysis of Surveillance, Epidemiology, and End Results (SEER) Program data from 1973 to 2011 identified 205 patients with mesenchymal chondrosarcoma; 82 patients had skeletal primary tumors, and 123 patients had extraskeletal tumors.[
A single-institution retrospective review identified 43 cases of mesenchymal chondrosarcoma from 1979 to 2010.[
Treatment
Treatment options for extraskeletal mesenchymal chondrosarcoma include the following:
A review of 15 patients younger than 26 years from the German Cooperative Soft Tissue Sarcoma Study Group (11 with soft-tissue lesions) and the German-Austrian-Swiss Cooperative Osteosarcoma Study Group (four with primary bone lesions) protocols suggests that complete surgical removal, or incomplete resection followed by radiation therapy, is necessary for local control.[
A single-institution, retrospective review identified 12 pediatric patients with mesenchymal chondrosarcoma.[
A Japanese study of patients with extraskeletal myxoid chondrosarcoma and mesenchymal chondrosarcoma randomly assigned patients to treatment with either trabectedin or best supportive care.[
Osteosarcoma, extraskeletal
Osseous and chondromatous neoplasms account for 0.8% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Extraskeletal osteosarcoma is extremely rare in the pediatric and adolescent population. An analysis of SEER data identified 256 patients (6%) with extraskeletal osteosarcoma among 4,173 patients with high-grade osteosarcoma from 1973 to 2009. Compared with skeletal osteosarcoma, patients with extraskeletal osteosarcoma were more likely to be older, female, have an axial primary tumor, and have regional lymph node involvement. Adverse prognostic features included presence of metastatic disease, larger tumor size, older age, and axial primary tumor site.[
Molecular features
A review of 32 adult patients with extraskeletal osteosarcomas consistently revealed several alterations.[
Prognosis
Extraskeletal osteosarcoma is associated with a high risk of local recurrence and pulmonary metastasis.[
In a review of 274 patients, with a median age of 57 years at diagnosis (range, 12–91 years), the 5-year DFS and OS rates were significantly better for those who received chemotherapy. The use of an osteosarcoma-type regimen was associated with improved response rates.[
The European Musculoskeletal Oncology Society performed a retrospective analysis of 266 eligible patients with extraskeletal osteosarcoma treated between 1981 and 2014.[
Treatment
Treatment options for extraskeletal osteosarcoma include the following:
Typical chemotherapy regimens used for osteosarcoma include some combination of cisplatin, doxorubicin, high-dose methotrexate, and ifosfamide.[
For more information about treatment of extraosseous osteosarcoma, including chemotherapy options, see Osteosarcoma and Undifferentiated Pleomorphic Sarcoma of Bone Treatment.
Fibroblastic and Myofibroblastic Tumors
Fibroblastic and myofibroblastic tumors have several subtypes, including the following:
Desmoid-type fibromatosis
Desmoid-type fibromatosis has previously been called desmoid tumors or aggressive fibromatoses.
Risk factors
Most desmoid tumors are sporadic, but a small proportion may occur in association with a mutation in the APC gene (associated with intestinal polyps and a high incidence of colon cancer). In a study of 519 patients older than 10 years with a diagnosis of desmoid-type fibromatosis, 39 patients (7.5%, a possible underestimation) were found to have familial adenomatous polyposis (FAP).[
A family history of colon cancer, the presence of congenital hyperplasia of the retinal pigment epithelium,[
Prognosis
Desmoid-type fibromatosis has an extremely low potential to metastasize. The tumors are locally infiltrating, and surgical control can be difficult because of the need to preserve normal structures.
Desmoid-type fibromatosis has a high potential for local recurrence. These tumors have a highly variable natural history, including well documented examples of spontaneous regression.[
Treatment
Evaluating the benefit of treatment interventions for desmoid-type fibromatosis has been extremely difficult, because desmoid-type fibromatosis has a highly variable natural history, with partial regressions seen in up to 20% of patients.[
Treatment options for desmoid-type fibromatosis include the following:
Treatment options under clinical evaluation
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Dermatofibrosarcoma protuberans NOS
Dermatofibrosarcoma is a rare tumor that can be present in all age groups, but many of the reported cases arise in children.[
Molecular features
The tumor has a consistent chromosomal translocation t(17;22)(q22;q13) that juxtaposes the COL1A1 gene with the PDGFRB gene.
Treatment
Treatment options for dermatofibrosarcoma protuberans include the following:
Most patients with dermatofibrosarcoma tumors can be cured by complete surgical resection. Wide excision with negative margins or Mohs/modified-Mohs surgery will prevent most tumors from recurring.[
The EpSSG prospective NRSTS 2005 (NCT00334854) trial identified 46 patients with dermatofibrosarcoma protuberans.[
In retrospective reviews, postoperative radiation therapy after incomplete excision may have decreased the likelihood of recurrence.[
When surgical resection cannot be accomplished or the tumor is recurrent, treatment with imatinib has been effective.[
A systematic review of nine studies examined 152 adult patients with histologically proven dermatofibrosarcoma protuberans who were treated with imatinib. The study demonstrated a complete response rate of 5.2%, a partial response rate of 55.2%, and a stable disease rate of 27.6%. There were no differences in the response rates based on imatinib dosing of either 400 mg or 800 mg per day.[
Guidelines for workup and management of dermatofibrosarcoma protuberans have been published.[
Inflammatory myofibroblastic tumor and epithelioid inflammatory myofibroblastic sarcoma
Inflammatory myofibroblastic tumor is a rare mesenchymal tumor that has a predilection for children and adolescents.[
For information about the treatment of this tumor in the lungs, see Childhood Pulmonary Inflammatory Myofibroblastic Tumors Treatment.
Clinical presentation
Inflammatory myofibroblastic tumors are rare tumors that affect soft tissues and visceral organs of children and young adults.[
Epithelioid inflammatory myofibroblastic sarcoma is an uncommon subtype of inflammatory myofibroblastic tumors. This subtype shows epithelioid morphology and a perinuclear or nuclear membrane pattern of immunostaining for ALK.[
Molecular features
Roughly one-half of inflammatory myofibroblastic tumors exhibit a clonal mutation that activates the ALK gene (encodes a receptor tyrosine kinase) at chromosome 2p23.[
Most cases of epithelioid inflammatory myofibroblastic sarcoma have an RANBP2::ALK gene fusion. An RRBP1::ALK gene fusion has also been reported.[
Prognosis
Inflammatory myofibroblastic tumor recurs frequently but is rarely metastatic.[
Epithelioid inflammatory myofibroblastic sarcoma is an aggressive tumor, and before the availability of ALK inhibitors, disease progression and high mortality rates were common.[
Treatment
Treatment options for inflammatory myofibroblastic tumor include the following:
Complete surgical removal, when feasible, is the mainstay of therapy.[
The benefit of chemotherapy has been noted in case reports.[
There are case reports of response to either steroids or NSAIDs.[
Inflammatory myofibroblastic tumors respond to ALK inhibitor therapy, as follows:
Patients with epithelioid inflammatory myofibroblastic sarcoma are generally treated with surgery. ALK inhibitors are often able to induce responses, although progression on therapy may occur.[
Infantile fibrosarcoma
There are two distinct types of fibrosarcoma in children and adolescents: infantile fibrosarcoma (also called congenital fibrosarcoma) and fibrosarcoma NOS that is indistinguishable from fibrosarcoma seen in adults. These are two distinct pathological diagnoses and require different treatments. Fibrosarcoma NOS is addressed below.
Clinical presentation
Infantile fibrosarcoma usually presents with a rapidly growing mass, often noted at birth or even seen in the prenatal ultrasound. The tumors are frequently quite large at the time of presentation.[
Molecular features
The tumor usually has a characteristic cytogenetic translocation t(12;15)(p13;q25) to create the ETV6::NTRK3 fusion gene. Infantile fibrosarcoma shares this translocation and a virtually identical histological appearance with mesoblastic nephroma.
Infantile fibrosarcoma usually occurs in children younger than 1 year. It occasionally occurs in children up to age 4 years. A tumor with similar morphology has been identified in older children; in these older children, the tumors do not have the ETV6::NRTK3 fusion that is characteristic of the younger patients.[
Prognosis
These tumors have a low incidence of metastases at diagnosis.
Treatment
Treatment options for infantile fibrosarcoma include the following:
Complete resection is curative in most patients with infantile fibrosarcoma. However, the large size of the lesion frequently makes resection without major functional consequences impossible. For instance, tumors of the extremities often require amputation for complete excision. The European pediatric group has reported that observation may also be an option in patients with group II disease after surgery.[
Preoperative chemotherapy has made a more conservative surgical approach possible. Agents active in this setting include vincristine, dactinomycin, cyclophosphamide, and ifosfamide.[
Two cases with variant LMNA::NTRK1 fusions responded to crizotinib.[
A phase I/II trial of larotrectinib was completed in patients with recurrent infantile fibrosarcoma who harbored an NTRK fusion. Larotrectinib is an oral ATP-competitive inhibitor of TRK A, B, and C. Durable objective responses were seen in all eight patients, and responses occurred at a median of 1.7 months. Most toxicities were grades 1 and 2, which included transaminitis, leukopenia, neutropenia, and vomiting. There were no grade 4 or grade 5 events attributed to larotrectinib.[
One of eight pediatric patients in this trial with an ETV6::NTRK3–rearranged infantile fibrosarcoma developed progressive disease after 8 months of larotrectinib therapy and was found to have a G623R acquired resistance mutation. The patient was treated with LOXO-195, a selective TRK inhibitor designed to overcome acquired resistance mediated by recurrent kinase domain mutations, and experienced a transient partial response.[
A patient aged 2 months with infantile fibrosarcoma was initially treated with chemotherapy. At disease progression, a response was seen with pazopanib therapy.[
A rare case of spontaneous regression without treatment has been reported.[
Treatment options under clinical evaluation
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following are examples of national and/or institutional clinical trials that are currently being conducted:
Patients with tumors that have molecular variants addressed by open treatment arms in the trial may be enrolled in treatment on Pediatric MATCH. Additional information can be obtained on the NCI website and ClinicalTrials.gov website.
The phase II subprotocol is evaluating larotrectinib in patients with tumors harboring actionable NTRK fusions.
Fibrosarcoma NOS
These tumors lack the translocation seen in infantile fibrosarcomas. They present like most nonrhabdomyosarcomas, and the management approach is similar.
Myxofibrosarcoma
Myxofibrosarcoma is a rare lesion, especially in childhood. It is typically treated with complete surgical resection.
Low-grade fibromyxoid sarcoma
Low-grade fibromyxoid sarcoma is a histologically deceptive soft tissue neoplasm that most commonly affects young and middle-aged adults. It is commonly located deep within the extremities, and it is characterized by a FUS::CREB3L2 translocation and, rarely, alternative translocations such as FUS::CREB3L1 and EWSR1::CREB3L1.[
Prognosis
In a review of 33 patients (3 were younger than 18 years) with low-grade fibromyxoid sarcoma, 21 patients developed a local recurrence after intervals of up to 15 years (median, 3.5 years). Fifteen patients developed metastases up to 45 years (median, 5 years) from diagnosis, most commonly to the lungs and pleura. This finding emphasizes the need for continued follow-up of these patients.[
In another report, 14 of 73 patients were younger than 18 years. In this series with a relatively short follow up (median of 24 months), only 8 of 54 patients with adequate follow-up developed local (9%) or distant (6%) recurrence. This report suggests that the behavior of this tumor might be significantly better than previously reported.[
A Children's Oncology Group (COG) trial (ARST0332 [NCT00346164]) enrolled 11 patients with this tumor entity. The median age at diagnosis was 13 years and males were more commonly affected. The most common tumor sites were the lower and upper extremity (n = 9). None of the patients developed local or distant disease recurrence at a median follow up of 2.7 years.[
Treatment
Treatment options for low-grade fibromyxoid sarcoma include the following:
Because low-grade fibromyxoid sarcoma is not very chemosensitive, the limited treatment information suggests that surgery is the treatment of choice.[
There are little data regarding the use of chemotherapy and/or radiation therapy in this disease. One report suggests that trabectedin may be effective in the treatment of low-grade fibromyxoid sarcoma.[
Sclerosing epithelioid fibrosarcoma
Sclerosing epithelioid fibrosarcoma is a rare malignant sarcoma that commonly harbors EWSR1 gene fusions and has an aggressive clinical course. The tumor is poorly responsive to chemotherapy.[
Genomic characteristics
Sclerosing epithelioid fibrosarcoma most commonly has the EWSR1::CREB3L1 gene fusion. However, EWSR1 may have other partners, including CREB3L2 and CREB3L3.[
Skeletal Muscle Tumors
Skeletal muscle tumors have several subtypes, including the following:
Rhabdomyosarcoma
For more information, see Childhood Rhabdomyosarcoma Treatment.
Ectomesenchymoma
Ectomesenchymoma is a rare nerve sheath tumor that mainly occurs in children. It is a biphenotypic soft tissue sarcoma with both mesenchymal and ectodermal components.
Treatment
Treatment options for ectomesenchymoma include the following:
The CWS reported on six patients (ages 0.2–13.5 years) registered over 14 years.[
Smooth Muscle Tumors
Leiomyosarcoma NOS
Leiomyosarcoma accounts for 2% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Risk factors
Among 43 children with HIV/AIDS who developed tumors, 8 developed Epstein-Barr virus–associated leiomyosarcoma.[
Treatment
Treatment options for leiomyosarcoma include the following:
Trabectedin has been studied in adults with leiomyosarcoma. Results from studies include the following:
There are no data to support the use of trabectedin in pediatric patients.
So-called Fibrohistiocytic Tumors
Plexiform fibrohistiocytic tumor
Plexiform fibrohistiocytic tumor is a rare, low- to intermediate-grade tumor that most commonly affects children and young adults. Depending on the series, the median age at presentation ranges from 8 to 14.5 years; however, the tumor has been described in patients as young as 3 months.[
Clinical presentation
The tumor commonly arises as a painless mass in the skin or subcutaneous tissue and most often involves the upper extremities, including the fingers, hand, and wrist.[
Molecular features
No consistent chromosomal anomalies have been detected but a t(4;15)(q21;q15) translocation has been reported.[
Prognosis
Plexiform fibrohistiocytic tumor is an intermediate-grade tumor that rarely metastasizes.
Treatment
Treatment options for plexiform fibrohistiocytic tumor include the following:
Peripheral Nerve Sheath Tumors
Peripheral nerve sheath tumors have several subtypes, including the following:
Malignant peripheral nerve sheath tumor NOS
Malignant peripheral nerve sheath tumors account for 5% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Risk factors
Malignant peripheral nerve sheath tumor can arise sporadically and in children with neurofibromatosis type 1 (NF1).[
A rare case of a child with documented neurofibromatosis type 2 (NF2) and a benign neurofibroma had five recurrences. During this time, the lesions progressively lost markers (such as S-100) and acquired clear-cut signs of malignant transformation to malignant peripheral nerve sheath tumor, documented by multiple markers, including the first example of NOTCH2 in this disease.[
Molecular features
Molecular features of malignant peripheral nerve sheath tumor include the following:
Prognosis
Features associated with a favorable prognosis include the following:[
Features associated with an unfavorable prognosis include the following:[
For patients with localized disease in the MD Anderson Cancer Center study, there was no significant difference in outcome between patients with and without NF1.[
The Italian Sarcoma Group reported on outcomes after recurrence in 73 children and adolescents with malignant peripheral nerve sheath tumor.[
The CWS reported a retrospective review of patients with malignant peripheral nerve sheath tumor who were treated on five consecutive CWS trials.[
Treatment
Treatment options for malignant peripheral nerve sheath tumor include the following:
Complete surgical removal of the tumor, whenever possible, is the mainstay of treatment.
The role of radiation therapy is difficult to assess, but durable local control of known postoperative microscopic residual tumor is not assured after radiation therapy.
For patients who received chemotherapy, treatment consisted of four courses of ifosfamide/doxorubicin and two courses of ifosfamide concomitant with radiation therapy (50.4–54 Gy). The response rate to chemotherapy (partial response + complete response) in patients with measurable disease was 46%. The presence of NF1 (51% of patients) was an independent poor prognostic factor for OS and EFS.
Recurrent malignant peripheral nerve sheath tumor
Of 120 patients enrolled in Italian pediatric protocols from 1979 to 2004, an analysis identified 73 patients younger than 21 years with relapsed malignant peripheral nerve sheath tumor. The time to relapse from initial diagnosis ranged from 1 month to 204 months, with a median time to relapse of 7 months. Median OS from first relapse was 11 months, with an OS rate of 39% at 1 year and 16% at 5 years. The factors associated with a higher probability of survival after relapse were lower tumor invasiveness at initial presentation, longer time to relapse, and complete surgical resection of the tumor at relapse.[
A retrospective study evaluated nine patients with unresectable or metastatic malignant peripheral nerve sheath tumor (seven patients were previously treated) who were treated with selinexor with or without doxorubicin. Three patients experienced a partial response that lasted for 3 months to longer than 8 months, and four patients had stable disease.[
Treatment options under clinical evaluation
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following are examples of national and/or institutional clinical trials that are currently being conducted:
Patients with tumors that have molecular variants addressed by open treatment arms in the trial may be enrolled in treatment on Pediatric MATCH. Additional information can be obtained on the NCI website and ClinicalTrials.gov website.
Malignant triton tumor
Malignant triton tumors are a variant of malignant peripheral nerve sheath tumors. They occur most often in patients with NF1 and consist of neurogenic and rhabdomyoblastic components. Malignant triton tumors are high-grade malignancies. They usually occur before age 35 years and are very rare in children (case reports only).[
Treatment
Malignant triton tumors are not usually responsive to chemotherapy and radiation therapy but have been treated with rhabdomyosarcoma therapy.[
Pericytic (Perivascular) Tumors
Pericytic (perivascular) tumors have several subtypes, including the following:
Myopericytoma
Infantile hemangiopericytoma, a subtype of myopericytoma, is a highly vascularized tumor of uncertain origin.
Children younger than 1 year with hemangiopericytoma seem to have a better prognosis than do children older than 1 year with hemangiopericytoma.[
Histology
Histologically, hemangiopericytomas are composed of packed round or fusiform cells that are arranged around a complex vasculature, forming many branch-like structures. Hyalinization is often present. Infantile hemangiopericytomas have similar histology but many are multilobular with vasculature outside the tumor mass.[
Treatment and outcome
Treatment options for infantile hemangiopericytomas include the following:
In a series of 17 children, the differences in metastatic potential and response to treatment were clearly demonstrated for adult and infantile hemangiopericytomas.[
Several studies have reported on tumors in children that were more akin to infantile myofibromatosis or hemangiopericytoma.[
Infantile myofibromatosis
This entity is a fibrous tumor of infancy and childhood that most commonly presents in the first 2 years of life.[
The lesion can present as a single subcutaneous nodule (myofibroma) most commonly involving the head and neck region, or lesions can affect multiple skin areas, muscle, and bone (myofibromatosis).[
An autosomal dominant form of infantile myofibromatosis has been described. It is associated with germline mutations of the PDGFRB gene, with the R561C variant being most commonly observed.[
The European Society for Paediatric Oncology Host Genome Working Group developed counseling and germline testing guidelines for these groups of children. This group recommends germline analysis for children with infantile myofibromatosis who have at least one of the following criteria:[
Somatic gain-of-function PDGFRB mutations have been identified in sporadic cases of infantile myofibromatosis, including activating point mutations and in-frame indels and duplications.[
Treatment and outcome
These lesions have an excellent prognosis and can regress spontaneously. About one-third of cases with multicentric involvement will also have visceral involvement, and the prognosis for these patients is poor.[
Treatment options for infantile myofibromatosis include the following:
The use of combination therapy with vincristine/dactinomycin and vinblastine/methotrexate have proven effective in cases of multicentric disease with visceral involvement and in cases in which the disease has progressed and has threatened the life of the patient (e.g., upper airway obstruction).[
Case reports have described prompt tumor regression in patients with infantile myofibromatosis that have PDGFRB mutations when treated with tyrosine kinase inhibitors like imatinib and sunitinib, which inhibit the gain-of-function mutated PDGFRB in the tumor.[
Tumors of Uncertain Differentiation
Tumors of uncertain differentiation have many subtypes, including the following:
Myxoma NOS
Carney complex
Carney complex is an autosomal dominant syndrome caused by mutations in the PPKAR1A gene, located on chromosome 17.[
For patients with the Carney complex, prognosis depends on the frequency of recurrences of cardiac and skin myxomas and other tumors.
For more information about the treatment of conditions related to Carney complex, see the following summaries:
Synovial sarcoma NOS
Synovial sarcoma accounts for 9% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Synovial sarcoma is one of the most common nonrhabdomyosarcomatous soft tissue sarcomas in children and adolescents. In a SEER review from 1973 to 2005, 1,268 patients with synovial sarcoma were identified. Approximately 17% of these patients were children and adolescents, and the median age at diagnosis was 34 years.[
Histological classification
Synovial sarcoma can be subclassified as the following types:
Clinical presentation
The most common tumor location is the extremities, followed by trunk and head and neck.[
The CWS reported on 432 patients younger than 21 years with synovial sarcoma between 1981 and 2018.[
The most common site of metastasis is the lung.[
Diagnostic evaluation and molecular features
The diagnosis of synovial sarcoma is made by immunohistochemical analysis, ultrastructural findings, and demonstration of the specific chromosomal translocation t(x;18)(p11.2;q11.2). This abnormality is specific for synovial sarcoma and is found in all morphological subtypes. Synovial sarcoma results in rearrangement of the SS18 gene on chromosome 18 with one of the subtypes (1, 2, or 4) of the SSX gene on chromosome X.[
In one report, reduced SMARCB1 nuclear reactivity on immunohistochemical staining was seen in 49 cases of synovial sarcoma, suggesting that this pattern may help distinguish synovial sarcoma from other histologies.[
Prognosis
Patients younger than 10 years have more favorable outcomes and clinical features than do older patients. Favorable clinical features include extremity primary tumors, smaller tumors, and localized disease.[
The following studies have reported multiple factors associated with unfavorable outcomes:
Treatment
Treatment options for synovial sarcoma include the following:
The COG and the EpSSG reported a combined analysis of 60 patients younger than 21 years with localized synovial sarcoma prospectively assigned to surgery without adjuvant radiation therapy or chemotherapy.[
Synovial sarcoma appears to be more sensitive to chemotherapy than many other soft tissue sarcomas. Children with synovial sarcoma seem to have a better prognosis than do adults with synovial sarcoma.[
Studies have reported the following chemotherapy-associated treatment findings:
Outcomes for patients treated on the CCLG-EPSSG-NRSTS-2005 trial are described in Table 12.
Risk Group | Treatment | 3-Year EFS (%) | 3-Year OS (%) |
---|---|---|---|
IRS = Intergroup Rhabdomyosarcoma Study; RT = radiation therapy. | |||
a Chemotherapy was ifosfamide/doxorubicin, with doxorubicin omitted during radiation therapy. | |||
b 59.4 Gy in cases without the option of secondary resection; 50.4 Gy as preoperative radiation therapy; 50.4, 54, and 59.4 Gy as postoperative radiation therapy, in the case of R0, R1, and R2 resections, respectively (no additional radiation therapy in the case of secondary complete resections with free margins, in children younger than 6 years). | |||
Low | Surgery alone | 92 | 100 |
Intermediate | Surgery, 3–6 cycles chemotherapya, ± RTb | 91 | 100 |
High (IRS group III) | 3 cycles of chemotherapya, surgery, 3 additional cycles of chemotherapy, ± RTb | 77 | 94 |
High (axial primary sites) | Surgery, 6 cycles of chemotherapya, RTb | 78 | 100 |
Recurrent synovial sarcoma NOS
Survival after relapse is poor (30%–40% at 5 years). Factors associated with outcome after relapse include duration of first remission (> or ≤ 18 months) and lack of a second remission.[
Radiation therapy (stereotactic body radiation therapy) can be used to target select pulmonary metastases. This is usually considered after a minimum of one resection to confirm metastatic disease. Radiation therapy is particularly appropriate for patients with lesions that threaten air exchange because of their location adjacent to bronchi or cause pain by invading the chest wall.[
Between 70% to 80% of synovial sarcomas express NY-ESO-1, an immunogenic cancer testis antigen.[
Treatment options under clinical evaluation
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Epithelioid sarcoma
Epithelioid sarcoma is a rare mesenchymal tumor of uncertain histogenesis that displays multilineage differentiation.[
Clinical presentation
Epithelioid sarcoma commonly presents as a slowly growing firm nodule based in the deep soft tissue. The proximal type predominantly affects adults and involves the axial skeleton and proximal sites. The tumor is highly aggressive and has a propensity for lymph node metastases.
Molecular features
Epithelioid sarcoma is characterized by inactivation of the SMARCB1 gene, which is present in both conventional and proximal types of epithelioid sarcoma.[
Treatment
Treatment options for epithelioid sarcoma include the following:
Patients should be carefully evaluated for the presence of involved lymph nodes; suspicious lymph nodes are biopsied. Surgical removal of primary and recurrent tumor(s) is the most effective treatment.[
In a review of 30 pediatric patients with epithelioid sarcoma (median age at presentation, 12 years), responses to chemotherapy were reported in 40% of patients using sarcoma-based regimens. Sixty percent of patients were alive at 5 years after initial diagnosis.[
In a German CWS retrospective analysis of 67 children, adolescents, and young adults (median age, 14 years) with epithelioid sarcoma, 53 patients presented with localized disease and 14 patients presented with metastatic disease.[
A retrospective analysis reviewed COG and EpSSG prospective clinical trials that enrolled patients younger than 30 years with epithelioid sarcoma.[
In a phase II trial of 62 adult patients with epithelioid sarcoma and documented loss of INI1 by immunohistochemistry or biallelic SMARCB1 (the gene that encodes INI1) alterations, tazemetostat showed clinical activity. There were 9 of 62 confirmed partial responses, with an objective response rate of 15% and a disease control rate of 26%. In January 2020, the U.S. Food and Drug Administration (FDA) granted accelerated approval for tazemetostat for adults and pediatric patients aged 16 years and older with metastatic or locally advanced epithelioid sarcoma who were not eligible for complete resection.[
Treatment options under clinical evaluation for epithelioid sarcoma
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Alveolar soft part sarcoma
Alveolar soft part sarcomas account for 1.4% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Clinical presentation
The median age at presentation is 25 years for patients with alveolar soft part sarcoma. This tumor most commonly arises in the extremities but can occur in the oral and maxillofacial region.[
In a series of 61 patients with alveolar soft part sarcoma who were treated in four consecutive CWS trials and the SoTiSaR registry, 46 patients presented with localized disease and 15 patients had evidence of metastasis at diagnosis.[
Molecular features
This tumor of uncertain histogenesis is characterized by a consistent chromosomal translocation t(X;17)(p11.2;q25) that fuses the ASPSCR1 gene with the TFE3 gene.[
Prognosis
Alveolar soft part sarcoma in children may have an indolent course.[
In a series of 19 treated patients with alveolar soft part sarcoma, one study reported a 5-year OS rate of 80%. The OS rate was 91% for patients with localized disease, 100% for patients with tumors 5 cm or smaller, and 31% for patients with tumors larger than 5 cm.[
A retrospective review of children and young adults younger than 30 years (median age, 17 years; range, 1.5–30 years) from four institutions identified 69 patients treated primarily with surgery between 1980 and 2014.[
In patients with alveolar soft part sarcoma, presentation with metastases is common and often has a prolonged indolent course. In a series of patients treated on consecutive studies from Germany, 15 of 61 patients (25%) presented with metastases, often miliary in nature. Despite lack of response to chemotherapy, the 5-year OS rate was 61%, with an EFS rate of 20%.[
Treatment
Treatment options for alveolar soft part sarcoma include the following:
The standard treatment approach is complete resection of the primary lesion.[
In a series of patients treated on consecutive studies from Germany, PFS for patients without metastases on presentation appeared to improve with complete resection of the primary tumor. The 5-year EFS rate was 100% for patients with completely resected tumors, compared with 50% for patients with microscopic or gross residual disease.[
In a series of 51 pediatric patients aged 0 to 21 years with alveolar soft part sarcoma, the OS rate was 78% at 10 years and the EFS rate was about 63%. Patients with localized disease (n = 37) had a 10-year OS rate of 87%. The 14 patients with metastases at diagnosis had a 10-year OS rate of 44%, partly resulting from surgical removal of primary tumor and lung metastases in some patients. Only 3 of 18 patients (17%) with measurable disease had a response to conventional antisarcoma chemotherapy, but two of four patients treated with sunitinib had a partial response.[
There have been sporadic reports of objective responses to treatment with interferon-alpha and bevacizumab.[
Studies of tyrosine kinase inhibitors have observed the following:
Treatment options under clinical evaluation for alveolar soft part sarcoma
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Clear cell sarcoma NOS
Clear cell sarcoma (formerly and inappropriately called malignant melanoma of soft parts) is a rare soft tissue sarcoma that typically involves the deep soft tissues of the extremities. It is also called clear cell sarcoma of tendons and aponeuroses. The tumor often affects adolescents and young adults.
Patients who have small, localized tumors with low mitotic rate and intermediate histological grade have the best outcomes.[
Clinical presentation
The tumor most commonly affects the lower extremity, particularly the foot, heel, and ankle.[
Molecular features
Clear cell sarcoma of soft tissue is characterized by an EWSR1::ATF1 or EWSR1::CREB1 fusion.[
Treatment
Treatment options for clear cell sarcoma of soft tissue include the following:
In a series of 28 pediatric patients reported by the Italian and German Soft Tissue Cooperative Studies, the median age at diagnosis was 14 years and the lower extremity was the most common primary site (50%). Surgery with or without radiation therapy is the treatment of choice and offers the best chance for cure. In this series, 12 of 13 patients with completely resected tumors were cured. For patients with more advanced disease, the outcome is poor and chemotherapy is rarely effective.[
Extraskeletal myxoid chondrosarcoma
Extraskeletal myxoid chondrosarcoma is relatively rare among soft tissue sarcomas, representing only 2.3% of all soft tissue sarcomas.[
Molecular features
Extraskeletal myxoid chondrosarcoma is a multinodular neoplasm. The rounded cells are arranged in cords and strands in a chondroitin sulfate myxoid background. Several cytogenetic abnormalities have been identified (see Table 2), with the most frequent being the EWSR1::NR4A3 fusion.[
Prognosis
The tumor has traditionally been considered to have low-grade malignant potential.[
Treatment
Treatment options for extraskeletal myxoid chondrosarcoma include the following:
Aggressive local control and resection of metastases led to OS rates of 87% at 5 years and 63% at 10 years. Tumors were relatively resistant to radiation therapy.[
There may be potential genetic targets for small molecules, but these should be studied as part of a clinical trial. In an adult study, six of ten patients who received sunitinib achieved partial responses.[
Extraskeletal Ewing sarcoma
For more information, see Ewing Sarcoma and Undifferentiated Small Round Cell Sarcomas of Bone and Soft Tissue Treatment.
Desmoplastic small round cell tumor
Desmoplastic small round cell tumor is a rare primitive sarcoma.
Clinical presentation
Desmoplastic small round cell tumor most frequently involves the peritoneum in the abdomen, pelvis, and/or peritoneum into the scrotal sac, but it may occur in the kidney or other solid organs.[
A large single-institution series of 65 patients compared CT scans (n = 54) with positron emission tomography (PET)-CT scans (n = 11). PET-CT scans had very few false-negative results and detected metastatic sites missed on conventional CT scans.[
Molecular features
Cytogenetic studies of these tumors have demonstrated the recurrent translocation t(11;22)(p13;q12), which has been characterized as a fusion of the WT1 and EWSR1 genes.[
Prognosis
The overall prognosis for desmoplastic small round cell tumor remains extremely poor, with reported rates of death at 90%. Greater than 90% tumor resection either at presentation or after preoperative chemotherapy may be a favorable prognostic factor for OS.[
Treatment
There is no standard approach to the treatment of desmoplastic small round cell tumor.
Treatment options for desmoplastic small round cell tumor include the following:
Complete surgical resections are rare and usually performed in highly specialized centers, but are critical for any improved survival. Successful treatment modalities include neoadjuvant Ewing-type chemotherapy, followed by complete surgical resection of the extensive intra-abdominal tumors, followed by total abdominal radiation therapy. With this multimodality therapy, survival can be achieved in 30% to 40% of patients at 5 years.[
The addition of hyperthermic intraperitoneal chemotherapy (HIPEC) to complete surgical resection (cytoreductive surgery) is a new technique first applied to children in 2006 in a phase I clinical trial. Cytoreductive surgery and HIPEC for desmoplastic small round cell tumors is part of a multidisciplinary approach and is only being done in highly specialized centers. Surgeries can last over 12 hours in duration, and technical aspects of this unique tumor resection should be considered. HIPEC is a method of local treatment that may provide more control of the microscopic intra-abdominal disease. The theory is that heat plus the chemotherapy that is instilled in the abdominal cavity after surgical resection (at the time of surgery) provides synergistic cytotoxicity to any microscopic cells remaining in the abdomen.[
A single-institution phase II study showed HIPEC to be a potentially promising addition to complete surgical resection. Fourteen patients with desmoplastic small round cell tumor and five patients with other sarcomas were enrolled. These highly selected patients had tumor limited to the abdominal cavity. They demonstrated a partial response to neoadjuvant Ewing-type chemotherapy, had complete surgical resections and received HIPEC using cisplatin, and received adjuvant total-abdominal radiation therapy followed by adjuvant chemotherapy. With this standardized approach, patients with desmoplastic small round cell tumors had an OS rate of 80% at 30 months and 40% at 50 months. Patients with desmoplastic small round cell tumors without liver metastasis had no intra-abdominal recurrences, whereas 87% of patients with liver metastasis or portal disease had a recurrence.[
Other centers have used this approach of cytoreductive surgery and HIPEC in patients with desmoplastic small round cell tumors. In a retrospective study from centers in France, patients were treated with cytoreductive surgery and HIPEC. Twenty-two patients were selected, and the median age at diagnosis was 14.8 years (range, 4.2–17.6 years). Seven patients had peritoneal mesotheliomas, seven patients had desmoplastic small round cells tumors, and eight patients had other histological types. A complete macroscopic resection (CC-0, where CC is completeness of cytoreduction) was achieved in 16 cases (73%). Sixteen patients (72%) relapsed after a median time of 9.6 months (range, 1.4–86.4 months). Nine patients (41%) died of disease relapse after a median time of 5.3 months (range, 0.1–36.1 months). Not all of the seven patients with desmoplastic small round cell tumors had complete resections.[
Another study from France reviewed the use of cytoreductive surgery and HIPEC for the treatment of patients with desmoplastic small round cell tumors who had disease limited to the abdomen. In 107 patients with desmoplastic small round cell tumors, 48 had no extraperitoneal metastasis and underwent cytoreductive surgery. Of 48 patients, 38 patients (79%) received preoperative and/or postoperative chemotherapy, and 23 patients (48%) received postoperative whole-abdominopelvic radiation therapy. Intraperitoneal chemotherapy was administered to 11 patients (23%); two patients received early postoperative intraperitoneal chemotherapy (EPIC) and nine patients received HIPEC. After a median follow-up of 30 months, the median OS of the entire cohort was 42 months. The 2-year OS rate was 72%, and the 5-year OS rate was 19%. The 2-year DFS rate was 30%, and the 5-year DFS rate was 12%. Whole-abdominopelvic radiation therapy was the only variable associated with longer peritoneal recurrence-free survival and DFS after cytoreductive surgery. Of 11 patients who received intraperitoneal chemotherapy (HIPEC or EPIC), six different chemotherapy regimens were used. The survival or outcome of this group is not reported in the manuscript. The influence of HIPEC/EPIC on OS and DFS was not statistically significant, but standardized regimens were not used in all patients, making results difficult to determine.[
A single-institutional retrospective study reported on nine patients with desmoplastic small round cell tumor. Most patients had widespread disease, including four patients with extraabdominal disease and five patients with liver involvement. These nine patients underwent ten cytoreductive and HIPEC treatments. Additionally, seven patients also received radiation therapy, and three patients underwent stem cell transplantation. The 3-year relapse-free survival rate was 13%, and the OS rate was 55%. Therapy was often associated with prolonged hospitalizations. Long-term parenteral nutrition was required in eight patients for a median of 261 days. Other long-term complications included gastroparesis (n = 1), small bowel obstruction (n = 3), and hemorrhagic cystitis (n = 2).[
The Center for International Blood and Marrow Transplant Research analyzed patients with desmoplastic small round cell tumor in their registry who received consolidation with high-dose chemotherapy and autologous stem cell reconstitution.[
A single-institution study reported that five of five patients with recurrent desmoplastic small round cell tumor had partial responses to treatment with the combination of vinorelbine, cyclophosphamide, and temsirolimus.[
Rhabdoid tumor NOS (extrarenal)
Malignant rhabdoid tumors were first described in children with renal tumors in 1981. These tumors were later found in a variety of extrarenal sites. These tumors are uncommon and highly malignant, especially in children younger than 2 years. For more information, see the Rhabdoid Tumors of the Kidney section in Wilms Tumor and Other Childhood Kidney Tumors Treatment.
Extrarenal (extracranial) rhabdoid tumors account for 2% of soft tissue sarcomas in patients younger than 20 years (see Table 1).
Molecular features
The first sizeable series of 26 children with extrarenal extracranial malignant rhabdoid tumor of soft tissues came from patients enrolled on the Intergroup Rhabdomyosarcoma Studies I through III during a review of pathology material. Only five patients (19%) were alive without disease.[
Prognosis
Young age and metastatic disease at presentation are associated with poor outcome in children with extracranial rhabdoid tumors.
One study that used data from the National Cancer Database identified 202 patients (aged younger than 18 years) with non-CNS malignant rhabdoid tumors.[
A SEER study examined 229 patients with renal, central nervous system (CNS), and extrarenal malignant rhabdoid tumor. Patient age of 2 to 18 years, limited extent of tumor, and delivery of radiation therapy were shown to affect the outcome favorably compared with other patients (P < .002 for each comparison). Site of the primary tumor was not prognostically significant. The OS rate was 33% at 5 years.[
A European registry for extracranial rhabdoid tumors identified 100 patients from 14 countries between 2009 and 2018.[
Treatment
Treatment options for extrarenal (extracranial) rhabdoid tumor include the following:[
Responses to alisertib have been documented in four patients with CNS atypical teratoid/rhabdoid tumors.[
Treatment options under clinical evaluation
Information about NCI-supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following are examples of national and/or institutional clinical trials that are currently being conducted:
Patients with tumors that have molecular variants addressed by open treatment arms in the trial may be enrolled in treatment on Pediatric MATCH. Additional information can be obtained on the NCI website and ClinicalTrials.gov website.
Perivascular epithelioid tumor (PEComa), malignant
Risk factors and molecular features
Benign PEComas are common in patients with tuberous sclerosis, an autosomal dominant syndrome that also predisposes to renal cell cancer and brain tumors. Tuberous sclerosis is caused by germline inactivation of either TSC1 (9q34) or TSC2 (16p13.3), and the same tumor suppressor genes are inactivated somatically in sporadic PEComas.[
Clinical presentation
PEComas occur in various rare gastrointestinal, pulmonary, gynecological, and genitourinary sites. Soft tissue, visceral, and gynecological PEComas are more commonly seen in middle-aged female patients and are usually not associated with the tuberous sclerosis complex.[
Prognosis
Most PEComas have a benign clinical course, but malignant behavior has been reported and can be predicted based on the size of the tumor, mitotic rate, and presence of necrosis.[
Treatment
Treatment options have not been defined. Treatment may include surgery or observation followed by surgery when the tumor is large.[
In tumors with evidence of mTORC1 activation and TSC1 or TSC2 loss, including lymphangioleiomyomatosis and angiomyolipoma,[
In a phase II trial, 34 patients with metastatic or locally advanced malignant PEComas were treated with sirolimus protein-bound particles for injectable suspension (albumin-bound) (nab-sirolimus). Of the 31 patients eligible for efficacy analysis, 12 (39%) had a response (1 complete response and 11 partial responses), 16 (52%) had stable disease, and 3 (10%) had progressive disease. Responses were rapid and durable. The median duration of response was not reached after a median follow-up of 2.5 years. Treatment was ongoing for 7 of 12 patients who responded to treatment (range, 5.6 months to longer than 47.2 months). Tumor mutational profiling was completed for 25 specimens. Eight of nine patients with TSC2 mutations responded to treatment, while only 2 of 16 patients without TSC2 mutations responded. In addition, responses were noted in 10 of 17 patients with phospho-S6 (pS6) expression. No response was noted in eight patients without pS6 expression. The absence of pS6 expression reflects the lack of mTORC1 activation.[
Undifferentiated sarcoma
From 1972 to 2006, patients with undifferentiated soft tissue sarcoma were eligible for participation in rhabdomyosarcoma trials coordinated by the IRS group and the COG. The rationale was that patients with undifferentiated soft tissue sarcoma had sites of disease and outcomes that were similar to those in patients with alveolar rhabdomyosarcoma. Therapeutic trials for adults with soft tissue sarcoma include patients with undifferentiated soft tissue sarcoma and other histologies, which are treated similarly, using ifosfamide and doxorubicin, and sometimes with other chemotherapy agents, surgery, and radiation therapy.
In the COG ARST0332 (NCT00346164) trial, patients with high-grade undifferentiated sarcoma were treated with an ifosfamide- and doxorubicin-based regimen. Results for the patients with high-grade undifferentiated sarcoma were reported together with all high-grade soft tissue sarcomas in the trial. The estimated 5-year EFS rate was 64% and the OS rate was 77% for sarcomas classified as high grade by the Fédération Nationale des Centres de Lutte Contre le Cancer.[
In a report of 32 patients with undifferentiated soft tissue sarcomas who were enrolled on the ARST0332 (NCT00346164) trial, the median age at enrollment was 13.6 years, and two-thirds of the patients were male. The most common primary sites were the paraspinal region and extremities. Five patients presented with metastatic disease.[
Pleomorphic sarcoma, undifferentiated (malignant fibrous histiocytoma)
At one time, malignant fibrous histiocytoma was the single most common histotype among adults with soft tissue sarcomas. Since it was first recognized in the early 1960s, malignant fibrous histiocytoma has been controversial, in terms of both its histogenesis and its validity as a clinicopathological entity. The latest WHO classification no longer includes malignant fibrous histiocytoma as a distinct diagnostic category but rather as a subtype of an undifferentiated pleomorphic sarcoma.[
This entity accounts for 2% to 6% of all childhood soft tissue sarcomas.[
Molecular features
An analysis of 70 patients who were diagnosed with malignant fibrous histiocytosis of no specific type, storiform or pleomorphic malignant fibrous histiocytoma, pleomorphic sarcoma, or undifferentiated pleomorphic sarcoma showed a highly complex karyotype with no specific recurrent aberrations.[
Undifferentiated sarcomas with 12q13–15 amplification, including MDM2 and CDK4, are best classified as dedifferentiated liposarcomas.[
Risk factors
These tumors can arise in previously irradiated sites or as a second malignancy in patients with retinoblastoma.[
Clinical presentation and treatment
These tumors occur mainly in the second decade of life. In a series of ten patients, the median age was 10 years, and the tumor was most commonly located in the extremities. In this series, all tumors were localized, and five of nine patients (for whom follow-up was available) were alive and in first remission.[
For more information about the treatment of malignant fibrous histiocytoma of bone, see Osteosarcoma and Undifferentiated Pleomorphic Sarcoma of Bone Treatment.
Treatment of recurrent or refractory pleomorphic sarcoma
Treatment options for recurrent or refractory pleomorphic sarcoma include the following:
The Sarcoma Alliance for Research through Collaboration conducted a phase II trial of the checkpoint inhibitor pembrolizumab in patients aged 18 years and older with recurrent soft tissue sarcoma.[
Round cell sarcoma, undifferentiated
Undifferentiated small round cell sarcomas withBCORgenetic alterations
For more information, see the sections on Undifferentiated Small Round Cell Sarcomas With BCOR Genetic Alterations and Genomics of Ewing Sarcoma in Ewing Sarcoma and Undifferentiated Small Round Cell Sarcomas of Bone and Soft Tissue Treatment.
Undifferentiated small round cell sarcomas withCICgenetic alterations
For more information, see the sections on Undifferentiated Small Round Cell Sarcomas With CIC Genetic Alterations and Genomics of Ewing Sarcoma in Ewing Sarcoma and Undifferentiated Small Round Cell Sarcomas of Bone and Soft Tissue Treatment.
Undifferentiated small round cell sarcomas withEWSR1–non-ETS fusions
For more information, see the Undifferentiated Small Round Cell Sarcomas With EWSR1–non-ETS Fusions section in Ewing Sarcoma and Undifferentiated Small Round Cell Sarcomas of Bone and Soft Tissue Treatment.
Vascular Tumors
Vascular tumors vary from hemangiomas, which are always considered benign, to angiosarcomas, which are highly malignant.[
Epithelioid hemangioendothelioma NOS
Incidence and outcome
Epithelioid hemangioendothelioma was first described in soft tissue by Weiss and Enzinger in 1982. These tumors can occur in younger patients, but the peak incidence is in the fourth and fifth decades of life. The tumors can have an indolent or very aggressive course, with an overall survival rate of 73% at 5 years. There are case reports of patients with untreated multiple lesions who have a very benign course. However, other patients have a very aggressive course. Some pathologists have tried to stratify patients to evaluate risks and adjust treatment, but more research is needed.[
A multi-institutional case series reported on 24 patients aged 2 to 26 years with epithelioid hemangioendotheliomas.[
The presence of effusions, tumor size larger than 3 cm, and a high mitotic index (>3 mitoses/50 high-power fields) have been associated with unfavorable outcomes.[
Clinical presentation and diagnostic evaluation
Common sites of involvement are liver alone (21%), liver plus lung (18%), lung alone (12%), and bone alone (14%).[
Histopathology and molecular features
A WWTR1::CAMTA1 gene fusion has been found in most patients. Less commonly, a YAP1::TFE3 gene fusion has been reported.[
Histologically, these lesions are characterized as epithelioid lesions arranged in nests, strands, and trabecular patterns, with infrequent vascular spaces. Features that may be associated with aggressive clinical behavior include cellular atypia, one or more mitoses per 10 high-power fields, an increased proportion of spindled cells, focal necrosis, and metaplastic bone formation.[
The number of pediatric patients reported in the literature is limited.
Treatment of epithelioid hemangioendothelioma
Treatment options for epithelioid hemangioendothelioma include the following:
For indolent cases, observation is warranted. Surgery is performed when resection is possible. Liver transplant has been used with aggressive liver lesions, both with and without metastases.[
For more aggressive cases, multiple medications have been used, including interferon, thalidomide, sorafenib, pazopanib, and sirolimus.[
A multi-institutional case series reported on 24 patients aged 2 to 26 years with epithelioid hemangioendothelioma.[
Patients or families who desire additional disease-directed therapy should consider entering trials of novel therapeutic approaches because no standard agents have demonstrated clinically significant activity.
Regardless of whether a decision is made to pursue disease-directed therapy at the time of progression, palliative care remains a central focus of management. This ensures that quality of life is maximized while attempting to reduce symptoms and stress related to the terminal illness.
Treatment options under clinical evaluation for epithelioid hemangioendothelioma
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
Current Clinical Trials
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
Angiosarcoma
Incidence and clinical presentation
Angiosarcoma is a rare (accounting for 2% of sarcomas), aggressive, vascular tumor that can arise in any part of the body but is more common in soft tissues. Angiosarcoma has an estimated incidence of 2 cases per 1 million people. In the United States, it affects approximately 600 people annually, who are typically aged 60 to 70 years.[
Angiosarcomas are extremely rare in children. It is unclear if the pathophysiology of angiosarcomas in children differs from that of angiosarcomas in adults. Cases have been reported in neonates and toddlers, with presentation of multiple cutaneous lesions and liver lesions, some of which are GLUT1 positive.[
Risk factors
Established risk factors include the following:[
Histopathology and molecular features
Angiosarcomas are largely aneuploid tumors. The rare cases of angiosarcoma that arise from benign lesions such as hemangiomas have a distinct pathway that needs to be investigated. MYC amplification is seen in radiation-induced angiosarcoma. KDR::VEGFR2 mutations and FLT4::VEGFR3 amplifications have been seen with a frequency of less than 50%.[
Histopathological diagnosis can be very difficult because there can be areas of varied atypia. A common feature of angiosarcoma is an irregular network of channels in a dissective pattern along dermal collagen bundles. There is varied cellular shape, size, mitosis, endothelial multilayering, and papillary formation. Epithelioid cells can also be present. Necrosis and hemorrhage are common. Tumors stain for factor VIII, CD31, and CD34. Some liver lesions can mimic infantile hemangiomas and have focal GLUT1 positivity. Nomenclature of these liver lesions has been difficult and confusing with use of outdated terminology proposed in 1971 (e.g., type I hemangioendothelioma: infantile hemangioma; type II hemangioendothelioma: low-grade angiosarcoma; type III hemangioendothelioma: high-grade angiosarcoma).[
Treatment of angiosarcoma
Treatment options for angiosarcoma include the following:
Localized disease can be cured by aggressive surgery. Complete surgical excision appears to be crucial for the long-term survival of patients with angiosarcomas and lymphangiosarcomas, despite evidence of tumor shrinkage in some patients who were treated with local or systemic therapy.[
Localized disease, especially cutaneous angiosarcomas, can be treated with radiation therapy. Most of these reported cases are in adults.[
Multimodal treatment with surgery, systemic chemotherapy, and radiation therapy is used for metastatic disease, although it is rarely curative.[
One child who was diagnosed with angiosarcoma secondary to malignant transformation from infantile hemangioma responded to treatment with bevacizumab (a monoclonal antibody against vascular endothelial growth factor) combined with systemic chemotherapy.[
Biologic agents that inhibit angiogenesis have shown activity in adults with angiosarcomas.[
There is one case report of a pediatric patient with metastatic cardiac angiosarcoma who was successfully treated with conventional chemotherapy, radiation, surgery, and targeted therapies, including pazopanib.[
Patients or families who desire additional disease-directed therapy should consider entering trials of novel therapeutic approaches because no standard agents have demonstrated clinically significant activity.
Regardless of whether a decision is made to pursue disease-directed therapy at the time of progression, palliative care remains a central focus of management. This ensures that quality of life is maximized while attempting to reduce symptoms and stress related to the terminal illness.
Treatment options under clinical evaluation for angiosarcoma
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following are examples of national and/or institutional clinical trials that are currently being conducted:
Current Clinical Trials
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
Current Clinical Trials
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References:
Standard treatment options for metastatic childhood soft tissue sarcoma include the following:
For treatment options, see the individual tumor type sections of the summary.
The prognosis for children with metastatic soft tissue sarcomas is poor.[
Pulmonary Metastases
Generally, a surgical procedure, with resection of all gross disease, should be considered for children with isolated pulmonary metastases.[
An alternative approach is focused radiation therapy (fractionated stereotactic radiation therapy), which has been successfully used in adults to control lesions. The estimated 5-year survival rate after thoracotomy for pulmonary metastasectomy has ranged from 10% to 58% in adult studies.[
References:
With the possible exception of infants with infantile fibrosarcoma, the prognosis for patients with progressive or recurrent disease is poor. No prospective trial has demonstrated that enhanced local control of pediatric soft tissue sarcomas will ultimately improve survival. Therefore, treatment should be individualized for the site of recurrence, biological characteristics of the tumor (e.g., grade, invasiveness, and size), previous therapies, and individual patient considerations. All patients with recurrent tumors should consider participating in clinical trials.
Treatment options for progressive or recurrent disease include the following:
Pazopanib has been approved for use in patients with recurrent soft tissue sarcoma. The clinical trial that led to the approval was limited to adults. The study demonstrated disease stabilization and prolonged time to progression; it did not demonstrate improved overall survival.[
One 13-year-old boy and one 14-year-old girl with multiply recurrent synovial sarcoma and lung metastases had responses to pazopanib for 14 and 15 months, respectively.[
Resection is the standard treatment for recurrent pediatric nonrhabdomyosarcomatous soft tissue sarcomas. If the patient has not yet received radiation therapy, postoperative radiation should be considered after local excision of the recurrent tumor. Limb-sparing procedures with postoperative brachytherapy have been evaluated in adults but have not been studied extensively in children. For some children with extremity sarcomas who have received previous radiation therapy, amputation may be the only therapeutic option.
Published results of two studies addressed the outcomes of children with relapsed synovial sarcoma. Most patients in one study had distant relapse (29 of 44 patients),[
Treatment Options Under Clinical Evaluation
Information about National Cancer Institute (NCI)–supported clinical trials can be found on the NCI website. For information about clinical trials sponsored by other organizations, see the ClinicalTrials.gov website.
The following is an example of a national and/or institutional clinical trial that is currently being conducted:
Patients with tumors that have molecular variants addressed by open treatment arms in the trial may be enrolled in treatment on Pediatric MATCH. Additional information can be obtained on the NCI website and ClinicalTrials.gov website.
Current Clinical Trials
Use our advanced clinical trial search to find NCI-supported cancer clinical trials that are now enrolling patients. The search can be narrowed by location of the trial, type of treatment, name of the drug, and other criteria. General information about clinical trials is also available.
References:
The PDQ cancer information summaries are reviewed regularly and updated as new information becomes available. This section describes the latest changes made to this summary as of the date above.
General Information About Childhood Soft Tissue Sarcoma
Revised text to state that between 1975 and 2020, childhood cancer mortality decreased by more than 50% (cited Surveillance Research Program, National Cancer Institute as reference 3).
Treatment of Newly Diagnosed Childhood Soft Tissue Sarcoma
Added Treatment options under clinical evaluation for epithelioid sarcoma as a new subsection.
Added text about the PEPN2121 clinical trial as a treatment option under clinical evaluation for children with extrarenal (extracranial) rhabdoid tumors.
This summary is written and maintained by the PDQ Pediatric Treatment Editorial Board, which is editorially independent of NCI. The summary reflects an independent review of the literature and does not represent a policy statement of NCI or NIH. More information about summary policies and the role of the PDQ Editorial Boards in maintaining the PDQ summaries can be found on the About This PDQ Summary and PDQ® Cancer Information for Health Professionals pages.
Purpose of This Summary
This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of childhood soft tissue sarcoma. It is intended as a resource to inform and assist clinicians in the care of their patients. It does not provide formal guidelines or recommendations for making health care decisions.
Reviewers and Updates
This summary is reviewed regularly and updated as necessary by the PDQ Pediatric Treatment Editorial Board, which is editorially independent of the National Cancer Institute (NCI). The summary reflects an independent review of the literature and does not represent a policy statement of NCI or the National Institutes of Health (NIH).
Board members review recently published articles each month to determine whether an article should:
Changes to the summaries are made through a consensus process in which Board members evaluate the strength of the evidence in the published articles and determine how the article should be included in the summary.
The lead reviewers for Childhood Soft Tissue Sarcoma Treatment are:
Any comments or questions about the summary content should be submitted to Cancer.gov through the NCI website's Email Us. Do not contact the individual Board Members with questions or comments about the summaries. Board members will not respond to individual inquiries.
Levels of Evidence
Some of the reference citations in this summary are accompanied by a level-of-evidence designation. These designations are intended to help readers assess the strength of the evidence supporting the use of specific interventions or approaches. The PDQ Pediatric Treatment Editorial Board uses a formal evidence ranking system in developing its level-of-evidence designations.
Permission to Use This Summary
PDQ is a registered trademark. Although the content of PDQ documents can be used freely as text, it cannot be identified as an NCI PDQ cancer information summary unless it is presented in its entirety and is regularly updated. However, an author would be permitted to write a sentence such as "NCI's PDQ cancer information summary about breast cancer prevention states the risks succinctly: [include excerpt from the summary]."
The preferred citation for this PDQ summary is:
PDQ® Pediatric Treatment Editorial Board. PDQ Childhood Soft Tissue Sarcoma Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/soft-tissue-sarcoma/hp/child-soft-tissue-treatment-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389361]
Images in this summary are used with permission of the author(s), artist, and/or publisher for use within the PDQ summaries only. Permission to use images outside the context of PDQ information must be obtained from the owner(s) and cannot be granted by the National Cancer Institute. Information about using the illustrations in this summary, along with many other cancer-related images, is available in Visuals Online, a collection of over 2,000 scientific images.
Disclaimer
Based on the strength of the available evidence, treatment options may be described as either "standard" or "under clinical evaluation." These classifications should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Managing Cancer Care page.
Contact Us
More information about contacting us or receiving help with the Cancer.gov website can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the website's Email Us.
Last Revised: 2022-12-07
This information does not replace the advice of a doctor. Healthwise, Incorporated, disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the
Healthwise, Healthwise for every health decision, and the Healthwise logo are trademarks of Healthwise, Incorporated.
Individual and family medical and dental insurance plans are insured by Cigna Health and Life Insurance Company (CHLIC), Cigna HealthCare of Arizona, Inc., Cigna HealthCare of Illinois, Inc., Cigna HealthCare of Georgia, Inc., Cigna HealthCare of North Carolina, Inc., Cigna HealthCare of South Carolina, Inc., and Cigna HealthCare of Texas, Inc. Group health insurance and health benefit plans are insured or administered by CHLIC, Connecticut General Life Insurance Company (CGLIC), or their affiliates (see
All insurance policies and group benefit plans contain exclusions and limitations. For availability, costs and complete details of coverage, contact a licensed agent or Cigna sales representative. This website is not intended for residents of New Mexico.