The impact of marital status on gastric cancer-related prognosis: A propensity-score matched study.

Gastric cancer remains a leading gastrointestinal malignancy with persistently high incidence and poor prognosis. Marital status, an established proxy for social support, has been linked to survival in several solid tumors, yet its impact on gastric-cancer outcomes remains uncertain in large contemporary cohorts. The aim of this study was to quantify the association between marital status and cancer-specific and overall survival in patients with gastric cancer in a large, contemporary, population-based cohort, and to determine whether marital status serves as an an independent prognostic factor for gastric-cancer outcomes. Using the surveillance, epidemiology, and end results database, we identified patients with primary gastric adenocarcinoma diagnosed from 2013 through 2022. Patients were dichotomized as married or unmarried. Baseline characteristics were compared with χ2 tests. To mitigate selection bias, 1:1 propensity-score matching (PSM) was performed. Cancer-specific survival (CSS) and overall survival (OS) were estimated with Kaplan-Meier and log-rank tests. Subgroup analyses and multivariable Cox regression were conducted to determine the independent prognostic value of marital status. A total of 39,013 patients were included (median follow-up 14 months). Before PSM, unmarried patients had significantly worse CSS (hazard ratio [HR] 1.17, 95% confidence interval [CI] 1.14-1.20, P < .001) and OS (HR 1.20, 95% CI 1.16-1.23, P < .001). After 1:1 PSM (15,256/group), the survival gap narrowed but remained significant (CSS: HR 1.12, P < .001; OS: HR 1.15, P < .001). Subgroup analyses showed unmarried status was consistently associated with poorer CSS and OS across most strata. Multivariable Cox regression confirmed unmarried status as an independent adverse prognostic factor for both CSS (HR 1.17, 95% CI 1.13-1.20, P < .001) and OS (HR 1.19, 95% CI 1.15-1.22, P < .001). In this large population-based cohort, unmarried status was independently associated with worse gastric-cancer outcomes. Marital status is a readily available marker of social and economic support that identifies patients at higher risk of adverse outcomes; these patients may benefit from targeted psychosocial, financial, and logistical support during and after treatment.