No significant differences were found between patients with UGT1A1*1/*28 and those with *1/*6 in the frequency of grade ≥3 neutropenia (50.0% vs. 50.0%, p = 1.00) and febrile neutropenia (10.0% and 8.3%, p = 1.00). Here, UGT1A1 is linked to Decreased total neutrophil count.