Note: Separate PDQ summaries on Stomach (Gastric) Cancer Screening, Gastric Cancer Treatment, and Levels of Evidence for Cancer Screening and Prevention Studies are also available.
Who Is at Risk?
People at elevated risk for gastric cancer include elderly patients with atrophic gastritis or pernicious anemia, patients with sporadic gastric adenomas, familial adenomatous polyposis, or hereditary nonpolyposis colon cancer, and immigrant ethnic populations from countries with high rates of gastric carcinoma.[4,5] Workers in the rubber and coal industries are also at increased risk.
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 factors include a family history of gastric cancer, Li Fruameni syndrome, and Type A blood type. Environmental factors include low consumption of fruits and vegetables; consumption of salted, smoked, or poorly preserved foods; cigarette smoking; and radiation exposure.[6,7,8]
There is consistent evidence that Helicobacter pylori infection, also known as H. pylori infection, of the stomach is strongly associated with both the initiation and promotion of carcinoma of the gastric body and antrum and of gastric lymphoma.[9,10,11] The International Agency for Research on Cancer classifies H. pylori infection as a cause of noncardia gastric carcinoma and gastric low-grade B-cell mucosa-associated lymphoid tissue or MALT lymphoma (i.e., a Group 1 human carcinogen).[12,13]
Compared with the general population, people with duodenal ulcer disease may have a lower risk of gastric cancer.
Interventions for Reduction of Stomach (Gastric) Cancer Risk
Based on solid evidence, smoking is associated with an increased risk of stomach cancer.[15,16,17] The 2004 Surgeon General's report identifies cigarette smoking as a cause of stomach cancer, with an average relative risk (RR) in former smokers of 1.2 and in current smokers of 1.6. Compared with persistent smokers, the risk of stomach cancer decreases among former smokers with time since cessation. This pattern of observations makes it reasonable to infer that cigarette smoking prevention or cessation would result in a decreased risk of gastric cancer.
Magnitude of Effect: A systematic review and meta-analysis showed a 60% increase in gastric cancer in male smokers and a 20% increase in gastric cancer in female smokers compared with nonsmokers.
|Study Design: Evidence obtained from case-control and cohort studies.|
|Internal Validity: Good.|
|External Validity: Good.|
H. Pyloriinfection eradication
Based on solid evidence, H. pylori infection is associated with an increased risk of gastric cancer. A meta-analysis of seven randomized studies, all conducted in areas of high-risk gastric cancer and all but one conducted in Asia, suggests that treatment of H. pylori may reduce gastric cancer risk (from 1.7% to 1.1%; RR = 0.65; 95% confidence interval, 0.43–0.98). Only two studies assessed gastric cancer incidence as the primary study outcome, and two different studies were double blinded. It is unclear how generalizable the results may be to the North American population.