Family history of cancer and stomach cancer risk.

A family history of stomach cancer in first-degree relatives increases the risk of stomach cancer, but uncertainties remain as concerns the variation of the risk according to age, sex and type of relative, as well as on the role of family history of other cancers. We investigated the issue using data from a multicentric case-control study conducted in Italy between 1997 and 2007 on 230 cases aged not more than 80 years, with histologically confirmed incident gastric cancer and 547 controls admitted to hospital for acute, non neoplastic conditions. Logistic regression models adjusted for the effect of sex, age, year of interview, education, body mass index (BMI), tobacco smoking and number of brothers and sisters were used to estimate the odds ratios (OR) of stomach cancer. Relative to subjects with no history, those with a family history of gastric cancer had an OR of 2.5 (95% confidence interval (CI) 1.5-4.2). No significant heterogeneity emerged according to sex or age of the proband or of the affected relative, or smoking habits, BMI and education of the proband. As suggested from previous studies the OR was higher when the affected relative was a sibling (OR=5.1, 95% CI: 1.3-20.6) rather than a parent (OR=2.2, 95% CI: 1.2-3.9), although the heterogeneity test was not significant. The risk of stomach cancer was not increased in subjects with a family history of cancer at any other site. The OR for all sites excluding stomach was 1.0 (95% CI: 0.7-1.4).