1233 Disaggregation of Gastric Cancer Risk Between Asian American Subgroups

Abstract

INTRODUCTION: Within the United States (US), 26,000 new cases of gastric cancer (GC) and over 10,000 related deaths occur annually. Within the US, Asians and Pacific Islanders (API) in aggregate are known to be at increased risk for GC. There is limited data regarding GC risk between API subgroups. While screening of the general American population is not cost-effective, improved understanding of GC risk by disaggregated API subgroups may allow for targeted and cost-effective endoscopic screening. METHODS: All incident cases of GC diagnosed in the years 2011-2014 were identified from the Surveillance, Epidemiology, and End Results Program registries incorporating California (CA) and Hawaii (HI). From these incidence registries, API subgroup of patients were identified: Korean (CA and HI), Japanese (CA and HI), Chinese (CA and HI), Vietnamese (CA only), Filipino (CA and HI), and Indian (CA only). API subgroup population estimates were obtained from the American Community Survey (ACS). The age-adjusted incidence rates per 100,000 population and 95% confidence intervals (CIs) were generated for each subgroup, and among non-Hispanic whites (NHWs) for reference. RESULTS: 2,132 incident API GCs, and 3,984 incident NHW GCs were identified. Significant differences in GC incidence exist between API subgroups. In CA, Koreans (23.4 per 100,000, 95% CI 15.8 to 31.0) and Japanese (21.4, CI 16.1 to 26.7) demonstrated high incidence, Chinese (11.0, CI 10.4 to 11.6) and Vietnamese (10.3, CI 7.8 to 12.8) demonstrated intermediate incidence, and Filipinos (4.6, CI 3.4 to 5.8) and Indians (3.7, CI 2.9 to 4.5) demonstrated low incidence (Figure 1). The incidence among NHWs in CA was 6.6 (CI 6.0 to 7.2). In HI, Koreans (16.3, CI 11.4 to 21.2) and Japanese (16.0, CI 12.5 to 19.5) demonstrated high incidence, while Filipino (5.0, CI 3.4 to 6.6) and Chinese (4.8, CI 2.1 to 7.5) demonstrated low incidence (Figure 2). The incidence among NHWs in HI was 4.7 (CI 3.1 to 6.3). CONCLUSION: Substantial heterogeneity in risk for GC exist between API subgroups. Koreans and Japanese are at highest risk, with incidence nearly five-fold higher than Filipinos and Indians. This suggests that the higher GC-risk in APIs in aggregate are driven by certain subgroups. This may hold implications for screening for GC. There is a lower incidence of GC in HI compared to CA, even within API subgroups. These differences may represent cohort effects from generational migration, or regional dietary and environmental differences.