Statistical analysis
Categorical features were presented as counts and proportions and examined by the chi-squared test. Continuously parameterized characteristics were reported as the median and interquartile range (IQR), and comparisons of continuous variables between cohorts were determined using the Mann–Whitney U test. In these tests, a two-tail P value of 0.05 was deemed to be statistically significant. Based on the maximum Youden index, the best cutoff value for continuous variables was determined by ROC curve analysis. OS rates were estimated using the Kaplan–Meier method, and Disparities between groups were evaluated by log-rank test. The prognostic index was calculated 