General Information About Small Intestine Cancer

Incidence and Mortality

Estimated new cases and deaths from small intestine cancer in the United States in 2020:[1 ]

• New cases: 11,110.
• Deaths: 1,700.

Adenocarcinoma, lymphoma, sarcoma, and carcinoid tumors account for the majority of small intestine malignancies, which, as a whole, account for only 4% of all gastrointestinal malignancies.[2 ,3 ,4 ,5 ]

Follow-up and Survivorship

As in other gastrointestinal malignancies, the predominant modality of treatment is surgery when resection is possible, and cure relates to the ability to completely resect the cancer.

Carcinoid tumors of the small intestine are covered elsewhere as a separate cancer entity. (Refer to the PDQ summary on Gastrointestinal Carcinoid Tumor Treatment [Adult] for more information.)

References:

1. American Cancer Society: Cancer Facts and Figures 2020. Atlanta, Ga: American Cancer Society, 2020. Available online. Last accessed January 17, 2020.
2. Chamberlain R, Ghalyaie N, Patil S: Small bowel cancer. In: DeVita VT Jr, Lawrence TS, Rosenberg SA, et al., eds.: DeVita, Hellman, and Rosenberg's Cancer : Principles & Practice of Oncology. 11th ed. Philadelphia, Pa: Wolters Kluwer, 2019, pp 884-94.
3. Serour F, Dona G, Birkenfeld S, et al.: Primary neoplasms of the small bowel. J Surg Oncol 49 (1): 29-34, 1992.
4. Matsuo S, Eto T, Tsunoda T, et al.: Small bowel tumors: an analysis of tumor-like lesions, benign and malignant neoplasms. Eur J Surg Oncol 20 (1): 47-51, 1994.
5. Chow JS, Chen CC, Ahsan H, et al.: A population-based study of the incidence of malignant small bowel tumours: SEER, 1973-1990. Int J Epidemiol 25 (4): 722-8, 1996.

Cellular Classification of Small Intestine Cancer

Tumors that occur in the small intestine include the following:

• Adenocarcinoma (majority of cases).
• Lymphoma (uncommon), which is usually of the non-Hodgkin type. (Refer to the PDQ summary on Adult Non-Hodgkin Lymphoma Treatment for more information.)
• Sarcoma (most commonly leiomyosarcoma and more rarely angiosarcoma or liposarcoma).
• Carcinoid tumors. (Refer to the PDQ summary on Gastrointestinal Carcinoid Tumor Treatment [Adult] for more information.)
• Gastrointestinal stromal tumors. (Refer to the PDQ summary on Gastrointestinal Stromal Tumors Treatment [Adult] for more information.)

Approximately 25% to 50% of the primary malignant tumors in the small intestine are adenocarcinomas, and most occur in the duodenum.[1 ] Small intestine carcinomas may occur synchronously or metachronously at multiple sites.

Leiomyosarcomas occur most often in the ileum.

Some 20% of malignant lesions of the small intestine are carcinoid tumors, which occur more frequently in the ileum than in the duodenum or jejunum and may be multiple.

It is uncommon to find malignant lymphoma as a solitary small intestine lesion.

References:

1. Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp. 221–34.

Stage Information for Small Intestine Cancer

The treatment sections of this summary are organized according to histopathologic type rather than stage.

AJCC Stage Groupings and TNM Definitions

The American Joint Committee on Cancer (AJCC) has designated staging by TNM (tumor, node, metastasis) classification to define small intestine cancer. This staging classification applies only to adenocarcinomas arising in the nonampullary duodenum and small intestine. Nonadenocarcinomas arising in the small intestine should have a TNM assigned but are not assigned a stage classification.[1 ]

Table 1. Definitions of Primary Tumor (T)^a

T Category	T Criteria
a Reprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
b For T3 tumors, the nonperitonealized perimuscular tissue is, for the jejunum and ileum, part of the mesentery and, for the duodenum in areas where serosa is lacking, part of the interface with the pancreas.
TX	Primary tumor cannot be assessed.
T0	No evidence of primary tumor.
Tis	High-grade dysplasia/carcinomain situ.
T1	Tumor invades the lamina propria or submucosa.
−T1a	Tumor invades the lamina propria.
−T1b	Tumor invades the submucosa.
T2	Tumor invades the muscularis propria.
T3	Tumor invades through the muscularis propria into the subserosa, or extends into nonperitonealized perimuscular tissue (mesentery or retroperitoneum) without serosal penetration.b
T4	Tumor perforates the visceral peritoneum or directly invades other organs or structures (e.g., other loops of small intestine, mesentery of adjacent loops of bowel, and abdominal wall by way of serosa; for duodenum only, invasion of pancreas or bile duct).

Table 2. Definitions of Regional Lymph Node (N)^a

N Category	N Criteria
a Reprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
NX	Regional lymph nodes cannot be assessed.
N0	No regional lymph node metastasis.
N1	Metastasis in one or two regional lymph nodes.
N2	Metastasis in three or more regional lymph nodes.

Table 3. Definitions of Distant Metastasis (M)^a

M Category	M Criteria
a Reprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
M0	No distant metastasis.
M1	Distant metastasis present.

Table 4. Prognostic Stage Groups for Adenocarcinoma^a

Stage	T	N	M
T = primary tumor; N = regional lymph node; M = distant metastasis.
a Reprinted with permission from AJCC: Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp 221–34.
0	Tis	N0	M0
I	T1−2	N0	M0
IIA	T3	N0	M0
IIB	T4	N0	M0
IIIA	Any T	N1	M0
IIIB	Any T	N2	M0
IV	Any T	Any N	M1

References:

1. Small Intestine. In: Amin MB, Edge SB, Greene FL, et al., eds.: AJCC Cancer Staging Manual. 8th ed. New York, NY: Springer, 2017, pp. 221–34.

Small Intestine Adenocarcinoma Treatment

Standard treatment options:

1. For resectable primary disease:
   • Radical surgical resection.[1 ,2 ]
2. For unresectable primary disease:
   • Surgical bypass of obstructing lesion.
   • Palliative radiation therapy.

Treatment options under clinical evaluation:

1. For unresectable primary disease:
   • Clinical trials evaluating methods to improve local control, such as the use of radiation therapy with radiosensitizers with or without systemic chemotherapy.
2. For unresectable metastatic disease:
   • Clinical trials evaluating the value of new anticancer drugs and biologicals (phase I and phase II studies).

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:

1. Rose DM, Hochwald SN, Klimstra DS, et al.: Primary duodenal adenocarcinoma: a ten-year experience with 79 patients. J Am Coll Surg 183 (2): 89-96, 1996.
2. North JH, Pack MS: Malignant tumors of the small intestine: a review of 144 cases. Am Surg 66 (1): 46-51, 2000.

Small Intestine Leiomyosarcoma Treatment

Standard treatment options:

1. For resectable primary disease:
   • Radical surgical resection.
2. For unresectable primary disease:
   • Surgical bypass of obstructing lesion and radiation therapy.
3. For unresectable metastatic disease:
   • Palliative surgery.
   • Palliative radiation therapy.
   • Palliative chemotherapy.

Treatment options under clinical evaluation:

• For unresectable primary or metastatic disease:
  • Clinical trials evaluating the value of new anticancer drugs and biologicals.

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.

Recurrent Small Intestine Cancer Treatment

Standard treatment options:

1. For metastatic adenocarcinoma or leiomyosarcoma:
   • No standard effective chemotherapy exists for patients with recurrent metastatic adenocarcinoma or leiomyosarcoma of the small intestine. These patients should be considered candidates for clinical trials evaluating the use of new anticancer drugs or biologicals in phase I and phase II trials.
2. For locally recurrent disease:
   • Surgery.
   • Palliative radiation therapy.
   • Palliative chemotherapy.
   • Clinical trials evaluating ways of improving local control, such as the use of radiation therapy with radiosensitizers with or without systemic chemotherapy.

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.

Changes to This Summary (01 / 29 / 2020)

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 Small Intestine Cancer

Updated statistics with estimated new cases and deaths for 2020 (cited American Cancer Society as reference 1).

This summary is written and maintained by the PDQ Adult 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® - NCI's Comprehensive Cancer Database pages.

About This PDQ Summary

Purpose of This Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about the treatment of small intestine cancer. It is intended as a resource to inform and assist clinicians who care for cancer 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 Adult 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:

• be discussed at a meeting,
• be cited with text, or
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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 reviewer for Small Intestine Cancer Treatment is:

• Valerie Lee, MD (Johns Hopkins University)

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.

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The preferred citation for this PDQ summary is:

PDQ® Adult Treatment Editorial Board. PDQ Small Intestine Cancer Treatment. Bethesda, MD: National Cancer Institute. Updated <MM/DD/YYYY>. Available at: https://www.cancer.gov/types/small-intestine/hp/small-intestine-treatment-pdq. Accessed <MM/DD/YYYY>. [PMID: 26389423]

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Last Revised: 2020-01-29