Data analysis
Statistical analysis was performed using R version 4.1.2. Descriptive statistics were used to analyze patient demographics, clinical characteristics, and outcomes. Data are reported as medians and interquartile range (IQR) or means and standard deviation (SD)where applicable. Comparisons of variables between the earlier cohort and the current cohort were analyzed for significance using the chi-square test and t-test. Continuous variables were compared by the two-tailed chi-square test and Fisher’s exact test where applicable. The level of significance was set for a p-value <0.05. Survival estimates were determined using the Kaplan-Meier method.
Event-free survival (EFS) was based on the time of diagnosis to the date of the first treatment outcome (death, relapse/progressive disease, abandonment, alive at last follow-up). Overall survival (OS)was based on the time of diagnosis until the patient’s death or the last follow-up if alive. The analysis of prognostic factors was based on the EFS and the comparison of curves by the log-rank test.