Comparison of the Kaplan–Meier curves of the cumulative incidence of leukopenia and G-CSF administration between the first administration and re-administration showed no significant differences (log-rank test, P = 0.63, P = 0.85, respectively), indicating that the risk of leukopenia and G-CSF administration was similar. This evidence concerns the gene CSF3 and Decreased total leukocyte count.