Background: Effects of UGT1A1*6 and UGT1A1*28 genetic polymorphisms on irinotecan-induced severe toxicities in Asian cancer patients are inconclusive. Also, ABCC2 c.3972C>T may affect toxicity of irinotecan. It was aimed to assess the aggregated risk of neutropenia or diarrhea in Asian cancer patients taking irinotecan and inherited UGT1A1*6, UGT1A1*28 or ABCC2 c.3972C>T genetic variants. Methods: Literature was searched in PubMed for eligible studies. Odds ratios (ORs) were measured using RevMan software where P-valuesT genetic variant were not significantly associated with neutropenia (OR 1.67; 95% CI 0.98–2.84; P=0.06) but reduced diarrhea significantly (OR 0.31; 95% CI 0.11–0.81; P=0.02). Conclusions: Both UGT1A1*6 and UGT1A1*28 genetic variants should screen in Asian cancer patients to reduce substantially irinotecan-induced severe toxicities.
