Relationship between glutathione-S-transferase P1 Ile105Val polymorphism and docetaxel neurosensory toxicity

Abstract

2527 Background: Glutathione-S-transferases (GST) regulate the cellular response to oxidative stress and various anticancer agents. We recently underlined the importance of oxidative stress in the side effects of taxanes [Alexandre et al,J Natl Cancer Inst 2006;98:236–44], and investigated the relationship between the GST isoforms M1, T1 and P1 genes polymorphisms and docetaxel-induced peripheral neuropathy. Methods: We retrospectively analysed GST polymorphisms in a cohort of cancer patients (pts) treated with docetaxel and entered in a clinical trial database. A clinical neurologic evaluation (according to the NCI-CTC v2.0) was performed at baseline and at each treatment cycle. The GST M1 (null genotype), GST T1 (null genotype), and GST P1 (Ile105Val and Ala114Val) polymorphisms were determined using PCR, followed by either sequencing or RFLP techniques. The relationship between GST polymorphisms and grade = 2 neurosenrory toxicity (NST) as primary endpoint was studied, using the Chi2-square (with Yates correction) and the Fischer’s two-tailed exact test. Results: Fifty-eight pts were included : F/M: 29/29; median age: 61 years (range: 47–75). Primary tumor: 27.6% breast, 27.6% prostate, 24.1% lung and 20.7% other cancers. Pts received docetaxel 75–100 mg/m2 given as single-agent. A total of 261 cycles were administered (median/pt: 4, range 2–12). Ten pts developed grade = 2 NST. Twenty-seven pts (47%) were homozygous for the GST P1 105Ile allele, and 31 pts were either homozygous or heterozygous for the GST P1 105Val allele. Grade = 2 NST was significantly more common in pts with GST P1 105Ile/105Ile genotype (8/27 pts, 30%) compared with patients with 105Ile/105Val or 105Val/105Val GSTP1 genotype (2/31 pts, 6,5%; P = 0.047). Pts who were genotyped as GST P1 105Ile/105Ile had a higher risk of developing a grade = 2 NST than did those with other GSTP1 genotypes (OR 6.11; 95% CI, 1.17–31.94; P < 0.05). Conclusions: We found a significant correlation between GST P1 105Ile homozygous genotype and the development of a docetaxel-induced peripheral neuropathy. No significant financial relationships to disclose.