BRCA1 and XRCC1 polymorphisms associated with survival in advanced gastric cancer treated with taxane and cisplatin.

This study evaluated the influence of genetic polymorphism influencing drug metabolism on survival in taxane- and cisplatin-treated advanced gastric cancer (AGC). Peripheral blood samples from 207 AGC patients treated with first-line chemotherapy of taxane and cisplatin were used. We investigated polymorphisms that influenced the metabolism of taxane (ATP-binding cassette transporter B1 (ABCB1)), cisplatin (glutathione S-transferase M1 (GSTM1), glutathione S-transferase P1 (GSTP1), glutathione S-transferase T1 (GSTT1), excision repair cross complementing 1 (ERCC1), X-ray Cross Complementing group 3 (XRCC3), X-ray Cross Complementing group 4 (XRCC4), X-ray Cross Complementing group 1 (XRCC1), breast cancer (BRCA1)), and 5-fluorouracil (methylene tetrahydrofolate reductase (MTHFR), thymidylate synthase (TYMS)). A total of 207 patients were enrolled between May 2004 and Dec 2008, and 200 patients were analyzed. The overall response rate was 38.5%. Time to progression and overall survival time were 4.3 +/- 0.19 months and 11.9 +/- 1.05 months, respectively. There was no significant association between genetic polymorphism and response rate. However, the BRCA1 mutant TT homozygote was associated with significant prolongation of overall survival (hazard ratio [HR] = 0.43; 95% confidence interval [CI], 0.20-0.92; P = 0.03) and progression-free survival (HR = 0.51; 95% CI, 0.26-1.00; P = 0.05). Also, the XRCC1 194 CT genotype was associated with inferior overall survival, relative to the XRCC1 194 CC homozygotes (HR = 1.49; 95% CI, 0.11-2.07; P = 0.018).These findings suggest that BRCA1 TT and XRCC1 194 CT genotypes could be modest prognostic markers of AGC response in taxane- and cisplatin-treated patients.