Purpose: Whether age and inter-individual variability of pharmacogenetics are risk factors for paclitaxel-induced peripheral neuropathy (PIPN) is inconclusive. This study was conducted to evaluate the influence of previously investigated single nucleotide polymorphisms (SNPs) and age, using genotype data from a prospective study of paclitaxel-related toxicity in Japanese patients with breast cancer.
Methods: Peripheral blood mononuclear cells from 127 Japanese women with breast cancer who received weekly adjuvant paclitaxel were used to genotypes SLCO1B3 T334G (rs4149117), CYP2C8 A1196G (rs10509681), ABCB1 C1236T (rs1128503), ABCB1 G2677T/A (rs2032582), and ABCB1 C3435T (rs1045642). Genotypic and clinical factors were investigated for associations with PIPN.
Results: Of the five SNPs evaluated, no SNPs were significantly associated with grade 2 or higher PIPN. However, ABCB1 1236 TT showed a trend to associate with grade 2 or higher PIPN compared to ABCB1 CT/CC (odds ratio 2.1, 95% CI 0.991-4.548, p = 0.051). In subgroup analysis, patients ≥60 years old with an ABCB1 1236 TT had a higher incidence of ≥grade 2 PIPN compared to patients with CT or CC genotype (p = 0.027). On multivariable analysis, age ≥60 years and the ABCB1 1236 TT showed a significant association with ≥grade 2 PIPN (p = 0.005 and p = 0.034, respectively).
Conclusions: ABCB1 1236 TT genotype and older age might be a predictor of PIPN, which diminishes quality of life of cancer survivors.
Keywords: ABCB1; CYP2C8; Older age; Paclitaxel-induced peripheral neuropathy; SLCO1B3.