The results showed that UGT1A1*28 wild type (TA6/6) had a higher incidence of grade 0–2 leukopenia than mutant type (TA6/7 + TA7/7) [RR = 1.17, 95%CI (1.02, 1.35), P = 0.03], and the results were statistically different. This evidence concerns the gene UGT1A1 and Decreased total leukocyte count.