Population-Based Analysis of Differences in Gastric Cancer Incidence Among Races and Ethnicities in Individuals Age 50 Years and Older

BACKGROUND & AIMS: There are racial and ethnic differences in the incidence of gastric adenocarcinoma worldwide and in the US. Based on a decision analysis, screening for noncardia gastric adenocarcinoma might be cost-effective for non-White individuals 50 years or older. However, a lack of precise, contemporary information on gastric adenocarcinoma incidence in specific anatomic sites for this age group has impeded prevention and early detection programs in the US. We aimed to estimate the differences in gastric adenocarcinoma incidence in specific anatomic sites among races and ethnicities in individuals 50 years or older. METHODS: We analyzed California Cancer Registry data from 2011 through 2015 to estimate incidences of gastric adenocarcinoma in specific anatomic sites for non-Hispanic White (NHW), non-Hispanic Black, Hispanic, and the 7 largest Asian American populations. We calculated the differential incidence between non-White groups and NHW using incidence rate ratios and 95% confidence intervals (CIs). RESULTS: Compared with NHW subjects, all non-White groups had significantly higher incidences of noncardia gastric adenocarcinoma; the incidence was highest among Korean American men 50 years and older (70 cases per 100,000). Compared with NHW subjects 50 years and older, the risk of noncardia gastric adenocarcinoma was 1.8-fold (95% CI, 1.37-2.31) to 7.3-fold (95% CI, 5.73-9.19) higher in most non-White groups and 12.0-fold (95% CI, 9.96-14.6) to 14.5-fold (95% CI, 12.5-16.9) higher among Korean American men and women 50 years and older, respectively. Compared with NHW men 50 years and older, all non-White men, except Japanese and Korean American men, had a significantly lower risk of cardia gastric adenocarcinoma. CONCLUSIONS: We identified several-fold differences in incidences of gastric adenocarcinoma in specific anatomic sites among racial and ethnic groups, with significant age and sex differences. These findings can be used to develop targeted risk reduction programs for gastric adenocarcinoma.