Statistical analysis

Stabilized inverse probability of treatment weighting (IPTW) based on propensity score was performed to control selection bias and potential confounding factors between groups in comparisons of outcome. The propensity score model included all the characteristics listed above. The ϰ2 tests were used to evaluate the differences in categorical variables between male and female. The standardized mean differences (SMD) were used to measure the balance of individual covariates before and after IPTW. IPTW‐adjusted Kaplan–Meier survival curves compared OS between sex groups. Time‐dependent Cox regression analysis estimated both unadjusted and IPTW‐adjusted hazard ratios (HRs) and 95% confidence intervals (CIs). Additionally, landmark analyses were conducted to assess survival before and after five years. Hypothesis testing was performed on two‐sided 5% significance levels. Multivariable cox regression was used to conduct sensitivity analysis. Statistical analyses were implemented in R version 3.6.0 (R Foundation for Statistical Computing).