Population-Based Analysis of the Interplay between Rurality and Race in Gastric Adenocarcinoma Survival

Despite growing efforts to understand how rurality impacts cancer outcomes, significant gaps remain in understanding its prognostic influence and its interaction with race in patients with gastric adenocarcinoma (GA).

Using the Surveillance, Epidemiology, and End Results (SEER) database, we evaluated the impact of rurality on cancer-specific survival (CSS) in 45,589 GA patients using Kaplan-Meier methods. A multivariable Weibull regression survival model was used to control for potential confounders. We assessed the interplay between race and rurality by evaluating how the association of rurality on CSS differed across race-stratified groups and through joint-effects analysis.

Most patients lived in urban areas (89.5% vs 10.5%). There were no significant differences in age and receipt of chemotherapy between rural and urban populations. Rural patients tended to be male, non-Hispanic White, and more likely to have received radiation but less likely to have undergone surgery. Patients residing in rural areas had significantly worse CSS [hazard ratio (HR) = 1.16; 95% CI: 1.12-1.20; p < 0.001] even after adjusting for potential confounders [adjusted HR = 1.15; 95% CI: 1.11-1.19; p < 0.001]. After stratifying by race, the impact of rurality was not observed in non-Hispanic Black patients (p = 0.223) and was most pronounced in non-Hispanic Asian and Pacific Islanders (p = 0.019).

Rurality was associated with worse prognosis in GA patients across most racial groups. These findings highlight the need for further research to understand the mechanisms underlying urban-rural disparities in GA outcomes to identify targeted interventions.