Disparities in Gastric Cancer Outcomes Among Asian Ethnicities in the USA

Background. Survival for gastric cancer is reportedly higher in Asians than for other races. It is unclear whether differences in outcome exist among Asian ethnicities. Our objective was to assess gastric cancer survival in Asian ethnic groups in a large heterogeneous population. Methods. Asian-Americans treated for gastric adenocarcinoma between 1988 and 2006 were identified from the Los Angeles County Cancer Surveillance Program. Patients were stratified and compared by ethnicity ( Korean, Japanese, Chinese, Vietnamese or Filipino). Results. Of the 1,817 Asian-Americans in the study cohort, 45% (n = 810) were Korean, 25% ( n = 462) were Chinese, 11% ( n = 193) were Japanese, 10% ( n = 188) were Filipino, and 9% ( n = 164) were Vietnamese. For the entire cohort Koreans and Filipinos had the longest and shortest median survival ( MS), respectively (22.4 and 10.3 months, respectively; P<0.001). Multivariate analysis demonstrated that Japanese and Filipino ethnicity independently predicted worse survival compared with Korean ethnicity [hazard ratio (HR) 1.37, 95% confidence interval (CI) 1.08-1.73, P = 0.008; and HR 1.71, 95% CI 1.37-2.13, P < 0.001, respectively]. In the surgical cohort, Koreans and Filipinos had the longest and shortest survival, respectively ( MS of 57.8 and 21.7 months, respectively; P < 0.001). Multivariate analysis of the surgical cohort also demonstrated that Japanese and Filipino ethnicity independently predicted worse survival compared with Korean ethnicity (HR 1.61, 95% CI 1.22-2.13, P < 0.001; and HR 1.66, 95% CI 1.24-2.22, P < 0.001, respectively). Conclusion. There are differences in gastric cancer survival among Asian ethnicities. Future studies addressing varying environmental exposures and molecular expression patterns in gastric cancer are warranted to better understand these disparities in outcome.