ABCB1 gene polymorphisms are associated with adverse reactions in fluoropyrimidine-treated colorectal cancer patients.

Aim: To find out whether SNPs in the transporter gene ATP-binding casette B1 (ABCB1) were related to adverse effects in colorectal cancer patients treated with 5-fluorouracil (5-FU) or capecitabine. Materials & methods: Patients treated with a 5-FU-based therapy (n = 67) or a capecitabine-based therapy (n = 74) were recruited and genotyped for the ABCB1 SNPs rs1128503 (C1236T), rs2032592 (G2677T/A) and rs1045642 (C3435T). Clinical data and adverse reactions were recorded. ABCB1 genotypes of patients were statistically analyzed for association with the most frequent adverse reactions. Results: Statistical associations were observed, suggesting a lower risk of neutropenia (p = 0.013) and hand–foot syndrome (HFS; p = 0.027) for the carriers of T variation for rs1128503 in capecitabine-treated patients, carriers of T variation for rs1045642 treated with capecitabine had a lower risk of HFS (p = 0.033), while those treated with 5-FU had a higher risk of diarrhea (p = 0.035), and carriers of T variation for rs2...