Statistical analysis
Continuous variables were analyzed using the t-test and are presented as means and standard deviations. Fisher’s exact test was used to compare categorical variables. Time-to-event analysis was performed using Kaplan–Meier curves, and the log-rank test was used to compare the differences between the groups. For all analyses, p values were two-sided, and statistical significance was set at p <0.05. JMP version 13 (SAS Institute Inc., Cary, NC, USA) was used for all the statistical analyses.