Statistical analysis
DSS
REGRESSION
Baseline categorical variables were described using frequencies with percentages. The optimal cutoff value of continuous variable age was calculated using the “surv_cutpoint” function of the “survminer” R package. Pearson’s chi-square test was used in the comparison of categorical data, while when frequencies were below 5, Fisher exact test was applied. All statistical analyses were performed using R software (version 4.1.0). We used Kaplan-Meier survival estimation along with the log-rank test to estimate the OS and DSS of the whole group of patients. The risk factors of OS and DSS were evaluated by Cox regression analysis and competing risk analysis, respectively. A two-sided P value < 0.05 was considered statistically significant.