Comparison of effects of UGT1A1*6 and UGT1A1*28 on irinotecan-induced adverse reactions in the Japanese population: analysis of the Biobank Japan Project

J Hum Genet. 2019 Dec;64(12):1195-1202. doi: 10.1038/s10038-019-0677-2. Epub 2019 Oct 4.


It has been reported that there are differences in effects on irinotecan-induced adverse reactions between UGT1A1*6 and UGT1A1*28. In order to compare those differences in the Japanese population, we examined the associations between UGT1A1 and irinotecan-induced adverse reactions using the BioBank Japan Project database. We genotyped UTG1A1*6 and UGT1A1*28 and conducted case-control analyses. A total of 651 patients (102 cases and 549 tolerant controls) were included in this study. The results showed that UGT1A1*6/*6 is a predictor of adverse drug reactions (ADRs) (p-value 0.00070, odds ratio 6.59, 95% confidence interval 2.33-18.6), whereas UGT1A1*6/*28 and UGT1A1*28/*28 were not. The subanalysis comprising only patients with UGT1A1*6/*6, UGT1A1*6/*28, and UGT1A1*28/*28 revealed a trend towards an increased risk of ADRs in patients with UGT1A1*6 (p-value 0.0092, odds ratio 4.39, 95% confidence interval 1.57-14.9). Multiple logistic regression analyses showed that use of platinum-based antineoplastic drugs and presence of UGT1A1*6/*6 were independent variables, significantly associated with ADRs. The diagnostic performance of a predictive model had a sensitivity of 49.0%, specificity of 70.1%, and a number needed to screen of 5.8. We concluded that UGT1A1 testing could be useful to predict irinotecan-induced ADRs, and that UTG1A1*6 rather than UGT1A1*28 contributed to ADR occurrence.

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Antineoplastic Agents / adverse effects*
  • Asian Continental Ancestry Group / genetics*
  • Biological Specimen Banks
  • Case-Control Studies
  • Drug-Related Side Effects and Adverse Reactions / genetics*
  • Female
  • Genotype
  • Glucuronosyltransferase / genetics*
  • Humans
  • Irinotecan / adverse effects*
  • Japan
  • Male
  • Middle Aged
  • Polymorphism, Genetic / genetics*


  • Antineoplastic Agents
  • Irinotecan
  • UGT1A1 enzyme
  • Glucuronosyltransferase