![]() |
|
Gastric cancer: Screening - Health Professional Information [NCI PDQ]
Purpose of This PDQ SummaryThis PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about gastric cancer screening. This summary is reviewed regularly and updated as necessary by the PDQ Screening and Prevention Editorial Board. Information about the following is included in this summary:
This summary is intended as a resource to inform clinicians and other health professionals about currently available gastric cancer screening modalities. The PDQ Screening and Prevention Editorial Board uses a formal evidence ranking system in reporting the evidence of benefit and potential harms associated with each screening modality. It does not provide formal guidelines or recommendations for making health care decisions. Information in this summary should not be used as a basis for reimbursement determinations. This summary is also available in a patient version, which is written in less technical language. Summary of EvidenceNote: Separate PDQ summaries on Gastric Cancer Prevention, Gastric Cancer Treatment, and Levels of Evidence for Cancer Screening and Prevention Studies are also available. Benefits Based on fair evidence, screening would not result in a decrease in mortality from gastric cancer in the U.S. population.
Description of the Evidence
Harms Based on solid evidence, endoscopic screening would result in uncommon but serious side effects associated with endoscopy, which may include perforation, cardiopulmonary events, aspiration pneumonia, and bleeding requiring hospitalization.
Description of the Evidence
SignificanceNatural History, Incidence, and Mortality Gastric cancer is the 14th most frequent cause of cancer mortality in the United States. In 2007, it is estimated that 21,260 Americans will be diagnosed with gastric cancer and 11,210 will die of it.[1] Two-thirds of people diagnosed with gastric cancer are older than 66 years. The disease is much more common in other countries, principally Japan, Central Europe, Scandinavia, Hong Kong, South and Central America, the Soviet Union, China, and Korea. Gastric cancer is a major cause of death worldwide, especially in developing countries.[2] The major type of gastric cancer is adenocarcinoma (90%). The remaining 10% include lymphomas, sarcomas, and other rare types.[3] Gastric adenocarcinomas can be further categorized into an intestinal type and a diffuse type.[4] Intestinal-type lesions are frequently ulcerative and occur in the distal stomach more often than the diffuse type. Diffuse type lesions are associated with a worse prognosis than the intestinal type. The intestinal type tends to predominate in geographic regions with a high incidence of gastric carcinoma. The decline in the incidence of gastric cancer worldwide is largely due to a decrease in the number of intestinal type lesions. Risk Factors The incidence of gastric cancer in the United States has decreased fourfold since 1930 to approximately 7 cases per 100,000 people. The reasons for this striking decrease in incidence are unknown but are suspected to be related to improved storage of food, or changes in diet such as decreased salt intake. Risk factors for gastric cancer include the presence of precursor conditions such as chronic atrophic gastritis and intestinal metaplasia, pernicious anemia, and gastric adenomatous polyps. Genetic and environmental factors include a family history of gastric cancer; low consumption of fruits and vegetables; consumption of salted, smoked, or poorly preserved foods; and cigarette smoking.[5] There is increasing evidence that Helicobacter pylori infection of the stomach is associated with both the initiation and promotion of gastric carcinoma and gastric lymphoma.[6,7,8] Compared with the general population, people with duodenal ulcer disease may have a lower risk of gastric cancer.[9] There is considerable dispute as to whether partial gastrectomy, especially Billroth II gastrectomy for benign causes, increases risk.[10,11]
References:
Evidence of BenefitGastroscopic examination has been proposed as a screening method for the early detection of gastric cancer. No randomized trials evaluating the impact of screening on mortality from gastric cancer have been reported, although a Japanese study randomizing municipalities within a prefecture is ongoing.[1] Time-trend analysis and case-control studies of gastric endoscopy suggest a twofold decrease in gastric cancer mortality in screened versus unscreened individuals;[2,3,4,5,6] however, this stands in contrast to studies of stronger design. A cohort study of 24,134 individuals with a follow-up period of 40 months did not demonstrate a statistically significant decrease in gastric cancer mortality among men or women who were screened compared with those who were not screened.[7] A larger prospective study examined the association between screening in the past 12 months and subsequent gastric cancer mortality and other-cause mortality. The risk of death from gastric cancer and from causes of death other than gastric cancer were reduced among those who had participated in gastric cancer screening programs, demonstrating a selection for healthier individuals into screening programs.[8] Another cohort study was conducted in Linqu County, China, where gastric cancer rates are high, in which over 4,000 adult residents were screened. Individuals were screened at an average of 4.5 year intervals, except for a high-risk subset (689 individuals) that was screened 2 years after the initial examination. Of the 85 cases of gastric cancer occurring in the cohort, 58 were detected with screening. No impact on gastric cancer mortality was observed among screened individuals. The standardized mortality ratio (SMR) for gastric cancer 10 years after the initial screen was 1.01 (95% confidence interval, 0.72–1.37). The SMR for all-cause mortality was significantly lower among participants since individuals with hypertension, liver disease, and chronic obstructive pulmonary disease were not eligible to participate.[9] The study was not designed to evaluate screening, and the intervals between screens were long. A screening study was begun in Venezuela in 1980, using radiographic fluorography.[10] The efficacy of this program in reducing mortality from stomach cancer was evaluated by means of a case-control study. Analyses determined that the tests were ineffective in reducing mortality from gastric cancer. In Japan, measurement of serum pepsinogen (PGI and PGII) levels in 5,113 subjects also screened by endoscopy (13 gastric cancers detected), used cut-off points for identifying risk for gastric cancer of less than 70 ng/mL for pepsinogen I and less than 3 for the PGI:PGII ratio. This combination provided a sensitivity of 84.6%, a specificity of 73.5%, a positive predictive value of 0.81%, and a negative predictive value of 99.6%.[11] There may be some justification for screening some populations of Americans at higher risk, although there is considerable discussion about how much incidence would make the examination worthwhile. Potential subgroups might include elderly with atrophic gastritis or pernicious anemia, patients with partial gastrectomy,[12] patients with the diagnosis of sporadic adenomas,[13] familial adenomatous polyposis,[14] or hereditary nonpolyposis colon cancer,[15] and immigrant ethnic populations from countries with high rates of gastric carcinoma.[16,17]
References:
Changes To This Summary (01/31/2008)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. This summary was renamed from Gastric Cancer Screening. PURPOSE OF THIS PDQ SUMMARY Added this new section. Questions or Comments About This SummaryIf you have questions or comments about this summary, please send them to Cancer.gov through the Web site’s Contact Form. We can respond only to email messages written in English. More InformationABOUT PDQ
ADDITIONAL PDQ SUMMARIES
IMPORTANT: This information is intended mainly for use by doctors and other health care professionals. If you have questions about this topic, you can ask your doctor, or call the Cancer Information Service at 1-800-4-CANCER (1-800-422-6237). Date Last Modified: 2008-01-31
|
|||||||||||||||||