Migration-Associated Variation in Gastric Cancer Risk in the United States: Implications for Risk Stratification.

Classic mid-20th-century migrant studies demonstrated that gastric cancer risk declines after migration but does not fully converge to host-country levels, implicating early-life exposures and long disease latency. Whether these migration-associated risk gradients remain detectable in contemporary low-incidence settings has not been systematically evaluated using modern U.S. cancer surveillance data. We analyzed SEER and state cancer registry data linked to U.S. Census-derived population denominators to estimate crude and age-adjusted gastric cancer incidence from 2010 to 2022 in California and New York. Asian populations were disaggregated into Chinese, Japanese, Korean, and Vietnamese subgroups. Temporal trends were assessed using Joinpoint regression, and U.S. incidence patterns were contextualized against country-of-origin incidence. Scenario-based extrapolations to 2035 were conducted. Gastric cancer incidence remained consistently higher among Asian populations than among non-Hispanic Whites, with age-adjusted incidence ranging from ~3.6-4.7 per 100,000 in non-Hispanic Whites versus 12-26 per 100,000 in Korean populations. Disaggregated analyses showed persistent differences across subgroups, with Korean populations consistently exhibiting the highest incidence. Incidence declined significantly over time in California (annual percent change ~-1% to -3%) but not in New York. Extrapolations suggest that a clinically meaningful burden will persist among high-risk subgroups through 2035. These findings demonstrate that migration-associated variation in gastric cancer risk remains detectable and prevention-relevant in contemporary U.S. populations, supporting migration-informed approaches to risk stratification and prevention.