Gastric cancer disparities across generations of Latino populations in the United States: Insights from the Multiethnic Cohort study

Background: Individuals of Latin American origin in the United States (US) have higher incidence of gastric cancer (GC) than the general population. The contribution of immigration history to this disparity remains inadequately characterized. This study assessed the association between generational immigration status and GC risk among Latino populations. Methods: We analyzed data from the population-based Multiethnic Cohort Study (MEC), which enrolled residents of Hawaii and California between 1993-1996. Participants who self-identified as Latino of Mexican, Central or South American descent were included, with non-Hispanic Whites (NHWs) as reference group. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for GC overall and by anatomical subtype. Results: Among 79,963 participants (median age 59 yr; 48% male), 377 incident GC cases were identified. Latino participants had around twice the risk of GC compared with NHWs. The risk remained stable across generations: first-generation (born in Mexico, Central/South America) had an HR of 2.17 (95%CI, 1.61-2.92); second-generation (US-born with one or both parents born in Mexico, Central/South America), HR 2.09 (95%CI, 1.56-2.80); and third-generation, HR 2.67 (95%CI, 1.87-3.82). No notable differences were observed across Mexican and Central/South American subgroups. Associations were stronger for non-cardia GC (HRs, 2.78, 2.62, and 3.42 for first-, second-, and third-generation, respectively) but were not significant for cardia GC. Conclusions: Latino descendants showed more than twofold higher GC risk compared to NHWs, with elevated risk persisting across generations. No attenuation among US-born individuals suggests lasting ancestral or biological susceptibilities beyond immigration-related exposures. These findings underscore the need to identify at-risk populations and guide targeted prevention strategies. Table 1. HRs of gastric cancer by generation status among Latino descendants Descendants NHW First Generation Second Generation Third Generation Latino Participants 39779 18720 14614 6850 Cases 103 123 104 47 HR (95%CI) 1.00 2.17(1.61-2.92) 2.09(1.56-2.80) 2.67(1.87-3.82) Mexico Participants 39779 13703 14156 6850 Cases 103 78 102 47 HR (95%CI) 1.00 1.77(1.27-2.48) 2.03(1.51-2.73) 2.63(1.84-3.77 Central/South America Participants 39779 5005 139 6850 Cases 103 45 1 47 HR (95%CI) 1.00 2.78(1.90-4.06) 1.92(0.27-13.76) 2.52(1.75-3.63)