2.4. Statistical analysis

Statistical differences in categorical variables were detected by the chi‐square (χ²) test or Fisher's exact test. Kaplan–Meier plots were generated to display survival data, and log‐rank test was used for between‐group comparisons. Parametric models based on Weibull distributions were performed for multivariate survival analysis as recommended, using WeibullReg() function in R package SurvRegCensCov (version 1.5). ^{24 , 25} Adjusted hazard ratios (HRs) with 95% confidence intervals (CIs) were calculated to show the impact of variables on OS and PFS. All statistical analyses were conducted by R version 4.2.1 (https://www.r‐project.org/). A two‐sided p value less than 0.05 was considered statistically significant.