Statistical analysis
Overall survival (OS) was calculated using the Kaplan–Meier method from
the first day of IREC administration to death or the last follow-up
visit. The cumulative incidence of relapse and non-relapse mortality was
calculated using the Gray test. We used the Chi-squared test to analyze
categorical variables and the Mann–Whitney U test to analyze continuous
variables. All statistical analyses were performed using EZR (Saitama
Medical Center, Jichi Medical University), which is a graphical user
interface for R (The R Foundation for Statistical Computing, Vienna,
Austria)14.