Polymorphism of CYP3A4 and ABCB1 genes increase the risk of neuropathy in breast cancer patients treated with paclitaxel and docetaxel

BACKGROUND Interindividual variability of pharmacogenetics may account for unpredictable neurotoxicities of taxanes. METHODS From March 2011 to June 2015, female patients with operable breast cancer who had received docetaxel- or paclitaxel-containing adjuvant chemotherapy were included in this study. All patients were treated with single-agent paclitaxel intravenously (IV) 175 mg/m(2) every 3 weeks for four cycles, or IV 80 mg/m(2) weekly for 12 cycles, and IV 100 mg/m(2) docetaxel for four cycles as adjuvant treatment. We evaluated the relationship between neurotoxicity of taxanes and single-nucleotide polymorphisms of ABCB1, CYP3A4, ERCC1, ERCC2, FGFR4, TP53, ERBB2, and CYP2C8 genes. Taxane-induced neurotoxicity during the treatment was evaluated according to the National Cancer Institute Common Toxicity Criteria version 4.03 prior to each cycle. Chi-squared tests were used to compare the two groups, and multivariate binary logistic regression models were used for determining possible risk factors of neuropathy. RESULTS Pharmacogenetic analysis was performed in 219 females. ABCB1 3435 TT genotype had significantly higher risk for grade ≥2 neurotoxicity (odds ratio [OR]: 2.759, 95% confidence interval [CI]: 1.172-6.493, P: 0.017) compared to TC and CC genotype, and also CYP3A4 392 AA and AG genotype had significantly higher risk for grade ≥2 neurotoxicity (OR: 2.259, 95% CI: 1.033-4.941, P: 0.038) compared to GG genotype. For FDGF4 gene with AG and GG genotype, OR was 1.879 (95% CI: 1.001-3.525, P: 0.048) compared to AA genotype with regard to any grade of neuropathy risk. We could not find any other association of other genotypes with neurotoxicity grades. CONCLUSION ABCB1 3435 TT genotype and CYP3A4 392 AA/AG genotypes may be used as predictors of neurotoxicity during taxane chemotherapy.