Abstract:

This study investigated the prevalence of UGT1A1 genotypes in patients at a specialized tertiary tumor hospital and examined the association between UGT1A1 gene polymorphisms and adverse reactions following irinotecan administration in real-world patients. We conducted a retrospective analysis of data from 42 patients who underwent UGT1A1 genetic testing between May 2017 and December 2021 at the hospital. We specifically focused on 31 of these patients, summarizing the occurrence of both hematological and non-hematological adverse reactions after irinotecan treatment. The findings revealed a heterozygous mutation rate of 21.9% for the UGT1A128 gene, a homozygous mutation rate of 4.9%, and a heterozygous mutation rate of 31.5% for the UGT1A16 gene. Notably, no homozygous mutations were detected. Analysis of patients with UGT1A1*6 and *28 heterozygous mutations showed no significant differences in hematological and non-hematological adverse reactions compared to wild-type patients. Hematological adverse reactions encompassed neutropenia, leukopenia, thrombocytopenia, and anemia, while non-hematological reactions included increased ALT/AST, ALP/GGT, bilirubin, as well as fatigue, nausea, vomiting, and delayed diarrhea. Remarkably, the incidence of delayed diarrhea in patients with UGT1A1*6 and *28 mutations was 100%, suggesting a higher risk in those with double mutations, warranting increased attention. In conclusion, while no significant differences in adverse reactions were observed between UGT1A1 heterozygous mutation patients and wild-type patients following irinotecan application, it is important to note that further confirmation of these findings is necessary through an expanded sample size.

Key words: Irinotecan, UGT1A1, Uridine diphosphate glucose uronate transferase, Genetic polymorphism, Adverse reactions