Abstract: The present invention concerns the methods and compositions for evaluating the risk of ironotecan toxicity in a cancer patient based on the genotype of the patient at position ?3156 of the UGT1A1 gene or at any position in linkage disequilibrium with the ?3156 variant.

Abstract: The present invention concerns the methods and compositions for evaluating the risk of ironotecan toxicity in a cancer patient based on the genotype of the patient at position ?3156 of the UGT1A1 gene or at any position in linkage disequilibrium with the ?3156 variant.

Abstract: Various embodiments of the invention include methods and compositions for evaluating the risk of irinotecan toxicity in a patient. In certain embodiments, the methods include detecting a promoter polymorphism in one or both UGT1A1 genes of the patient. In particular embodiments the promoter polymorphism is a single nucleotide polymorphism and may be in linkage disequilibrium with a UGT1A1 (TA)n repeat. The methods may include obtaining a nucleic acid sample from the patient and detecting the presence or absence of a promoter polymorphism. The promoter polymorphism may be at nucleotide position −3440, −3401, −3279, −3177, −3175, or −3156 from the UGT1A1 gene transcriptional start site. The number of TA repeats can be 5, 6, 7, 8 more TA repeats. In particular embodiments, the promoter polymorphism is a −3440C>A, −3401T>C, −3279G>T, −3177C>G, −3175A>G, −3156G>A polymorphism or any combination thereof.