A real-world 1:1 propensity-matched study revealed unmarried status was independently associated with worse survival for patients with renal clear cell carcinoma

Background: Marital status has been reported as an independent prognostic factor for survival in various cancers, but it has been rarely studied in renal clear cell carcinoma (ccRCC). In this study, we aimed to assess the impact of marital status on the survival of ccRCC patients. Methods: We retrospectively investigated the Surveillance, Epidemiology, and End Results (SEER) database and identified 68599 of ccRCC patients between 1973 and 2015. These patients were divided into married, single, divorced and widowed groups. The survival differences among these groups were assessed by Kaplan-Meier method and log-rank test. Multivariate Cox regression analyses were performed to identify the overall survival (OS) and cancer-specific survival (CSS) independent factors. Furthermore, 1:1 propensity score matching (PSM) analysis was performed to minimize the potential confounding factors. Results: Of the 68599 ccRCC patients, 44553 (64.95%) patients were married, 7410 (10.80%) were divorced, 10663 (15.54%) were single, and 5973 (8.71%) were widowed. The 5-year OS was 79.0%, 73.8%, 77.3%, and 66.4 % in the married, divorced, single, and widowed groups, respectively (p = 0.001) and the corresponding 5-year CSS rates were 85.5%, 83.3%, 80.8%, 76.5%, respectively. Multivariate Cox regression analysis marital status was the independent prognostic factor for OS and CSS. Compared with the married patients, the divorced, single, and widowed patients faced increased higher mortality risks for OS and CSS. In stratified analyses by sex, surgery conditions and cancer stages, those unmarried patients still had worse prognosis. The results were further confirmed in the 1: 1 matched group. Conclusion: Unmarried ccRCC patients experienced worse survival than their married counterparts. Among the unmarried patients, the widowed suffered the highest mortality risks for OS and CSS.