A pharmacogenetic analysis of peripheral sensory neuropathy related to administration of taxanes in breast cancer patients.

Abstract

e13133 Background: Commonly used in the treatment of breast cancer, the taxane class includes paclitaxel and docetaxel. Both medications are primarily metabolized by cytochrome P450 enzymes and transporters mediate drug membrane influx and efflux. Variability in metabolizing enzymes and drug transporter function can affect drug clearance. This study sought to determine if the presence of pharmacogenetic changes in metabolizing enzymes and transporters resulted in a patient experiencing peripheral sensory neuropathy. Methods: In this case-control study, patients were enrolled between April 13, 2018 and April 30, 2018. Electronic medical records of patients with current appointments at Cone Health Cancer Center- Wesley Long were reviewed to identify patients who completed treatment with taxanes for breast cancer after January 1, 2017 for evaluation for inclusion in the study. Buccal swabs for pharmacogenetics testing were collected. Genes of interest, ABCB1, CYP3A4, CYP3A5, and SLCO1B1, were evaluated and data was categorized by phenotype. Baseline characteristics and phenotype results were compared using Fisher's exact test for categorical variables and Wilcoxon Rank Sum for numeric variables as appropriate. Results: Thirty-three patients were included in the final analysis. The population was mainly white at 72% and all patients in the study were female. The average patient age was 57 years old. Most patients had stage 1 breast cancer. Most patients received docetaxel. Among patients with peripheral sensory neuropathy, nine were grade 1, five were grade 2, and seven were grade 3. Resulting phenotypes: CYP3A5, all patients were normal metabolizers. CYP3A5, 7 normal metabolizer, 4 intermediate, and 22 poor. SLCO1B1, 25 normal function, 8 intermediate, and no low. ABCB1, 13 normal function, 7 intermediate, and 13 low. For all genes, there was no statistically significant difference in phenotype between the neuropathy and no neuropathy study arms, CYP3A5 (p = 0.075) SLCO1B1 (p = 0.106), ABCB1 (p = 0.902). Conclusions: The findings of our study indicate that having pharmacogenetics changes in the genes, ABCB1, CYP3A4, CYP3A5, and SLCO1B1 did not influence the patients experience with peripheral sensory neuropathy.