Summary of Evidence

Note: Separate PDQ summaries on Stomach (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

• Study Design: Evidence obtained from case-control studies.
• Internal Validity: Fair.
• Consistency: Multiple studies, large number of participants.
• Magnitude of Effects on Health Outcomes: Fair evidence for no reduction in mortality.
• External Validity: Fair.

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

• Study Design: Evidence obtained from well-designed and conducted case-control studies.
• Internal Validity: Fair.
• Consistency: Multiple studies, large number of participants.
• Magnitude of Effects on Health Outcomes: Good evidence for rare but serious harms.

Significance

Natural History, Incidence, and Mortality

In 2011, it is estimated that 21,520 Americans will be diagnosed with gastric cancer and 10,340 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 seven 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 Benefit

Gastroscopic 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 patients 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:

Get More Information From NCI

Call 1-800-4-CANCER

For more information, U.S. residents may call the National Cancer Institute's (NCI's) Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237) Monday through Friday from 8:00 a.m. to 8:00 p.m., Eastern Time. A trained Cancer Information Specialist is available to answer your questions.

Chat online

The NCI's LiveHelp® online chat service provides Internet users with the ability to chat online with an Information Specialist. The service is available from 8:00 a.m. to 11:00 p.m. Eastern time, Monday through Friday. Information Specialists can help Internet users find information on NCI Web sites and answer questions about cancer.

Write to us

For more information from the NCI, please write to this address:

Search the NCI Web site

The NCI Web site provides online access to information on cancer, clinical trials, and other Web sites and organizations that offer support and resources for cancer patients and their families. For a quick search, use the search box in the upper right corner of each Web page. The results for a wide range of search terms will include a list of "Best Bets," editorially chosen Web pages that are most closely related to the search term entered.

There are also many other places to get materials and information about cancer treatment and services. Hospitals in your area may have information about local and regional agencies that have information on finances, getting to and from treatment, receiving care at home, and dealing with problems related to cancer treatment.

Find Publications

The NCI has booklets and other materials for patients, health professionals, and the public. These publications discuss types of cancer, methods of cancer treatment, coping with cancer, and clinical trials. Some publications provide information on tests for cancer, cancer causes and prevention, cancer statistics, and NCI research activities. NCI materials on these and other topics may be ordered online or printed directly from the NCI Publications Locator. These materials can also be ordered by telephone from the Cancer Information Service toll-free at 1-800-4-CANCER (1-800-422-6237).

Changes to This Summary (07 / 15 / 2011)

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.

Significance

Updated statistics with estimated new cases and deaths for 2011 (cited American Cancer Society as reference 1).

Questions or Comments About This Summary

If 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 Information

About PDQ

• PDQ® - NCI's Comprehensive Cancer Database.

  Full description of the NCI PDQ database.

Additional PDQ Summaries

• PDQ® Cancer Information Summaries: Adult Treatment

  Treatment options for adult cancers.

• PDQ® Cancer Information Summaries: Pediatric Treatment

  Treatment options for childhood cancers.

• PDQ® Cancer Information Summaries: Supportive and Palliative Care

  Side effects of cancer treatment, management of cancer-related complications and pain, and psychosocial concerns.

• PDQ® Cancer Information Summaries: Screening/Detection (Testing for Cancer)

  Tests or procedures that detect specific types of cancer.

• PDQ® Cancer Information Summaries: Prevention

  Risk factors and methods to increase chances of preventing specific types of cancer.

• PDQ® Cancer Information Summaries: Genetics

  Genetics of specific cancers and inherited cancer syndromes, and ethical, legal, and social concerns.

• PDQ® Cancer Information Summaries: Complementary and Alternative Medicine

  Information about complementary and alternative forms of treatment for patients with cancer.

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).

About This PDQ Summary

Purpose of This Summary

This PDQ cancer information summary for health professionals provides comprehensive, peer-reviewed, evidence-based information about stomach (gastric) cancer screening. 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 Screening and Prevention Editorial Board. Board members review recently published articles each month to determine whether an article should:

• be discussed at a meeting,
• be cited with text, or
• replace or update an existing article that is already cited.

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.

Any comments or questions about the summary content should be submitted to Cancer.gov through the Web site's Contact Form. 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 Screening and Prevention 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:

National Cancer Institute: PDQ® Stomach (Gastric) Cancer Screening. Bethesda, MD: National Cancer Institute. Date last modified <MM/DD/YYYY>. Available at: http://cancer.gov/cancertopics/pdq/screening/gastric/HealthProfessional. Accessed <MM/DD/YYYY>.

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

The information in these summaries should not be used as a basis for insurance reimbursement determinations. More information on insurance coverage is available on Cancer.gov on the Coping with Cancer: Financial, Insurance, and Legal Information page page.

Contact Us

More information about contacting us or receiving help with the Cancer.gov Web site can be found on our Contact Us for Help page. Questions can also be submitted to Cancer.gov through the Web site's Contact Form.

Last Revised: 2011-07-15