The relationship between marital status and survival in primary bone cancer: a population-based study

Background: Previous studies have demonstrated a significant impact of marital status on the prognosis of various cancers; however, its specific influence on the prognosis of primary bone cancer remains insufficiently investigated. In this study, we aimed to investigate the survival differences between male and female in patients diagnosed with primary bone cancer. Methods: Surveillance, Epidemiology, and End Results (SEER) database was utilized to identify suitable patients. Patients were categorized into married and unmarried groups, with a 1:1 propensity score matching (PSM) method used to balance baseline characteristics between the two groups. Kaplan-Meier curves and Log-rank tests were then employed to ascertain differences in overall survival (OS) and cancer-specific survival (CSS) between the groups, followed by gender-based subgroup analyses. A multivariate Cox regression was finally conducted to adjust for the effects of covariates. Results: A total of 8,208 patients were included in this study, comprising 4,650 married and 3,558 unmarried individuals. Significant baseline characteristic differences were observed between the two groups before PSM. After PSM, 3,138 patients from each group were included, with balance maintained in all considered baseline characteristics. Before PSM, married patients had better OS [hazard ratio (HR) =0.93, 95% confidence interval (CI): 0.87-0.99, P=0.047] compared to unmarried patients, but no significant difference in CSS (HR =0.95, 95% CI: 0.88-1.03, P=0.21). Following PSM, married patients exhibited significantly better OS (HR =0.85, 95% CI: 0.79-0.92, P<0.001) and CSS (HR =0.92, 95% CI: 0.84-0.99, P=0.045) than unmarried patients. However, in subgroup analyses, the survival benefit attributed to marriage was observed only in females, not in males. In Cox regression, marriage was identified as an independent protective factor for OS (HR =0.86, 95% CI: 0.79-0.93, P<0.001) and CSS (HR =0.91, 95% CI: 0.82-0.97, P=0.04). Conclusions: In patients with primary malignant bone cancer, marriage is a protective factor for survival, but this effect appears to be limited to females.