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.