Impact of the UGT1A1*28 allele on response to irinotecan: a systematic review and meta-analysis.

Pre-emptive irinotecan dose reduction for UGT1A1*28 homozygotes may result in reduced risk of severe neutropenia and diarrhea. However, clinical utility and cost-effectiveness are dependent upon such a dose reduction not impacting irinotecan efficacy. Whether UGT1A1*28 genotype is associated with irinotecan response therefore is an important gap in existing knowledge to inform clinical utility.