XRCC1 and ERCC1 polymorphisms are related to susceptibility and survival of colorectal cancer in the Chinese population

Excision repair cross complementing group 1 (ERCC1) and X-ray repair cross-complementing groups 1 (XRCC1) are DNA repair enzymes. Polymorphisms in DNA repair genes may be important factors affecting cancer susceptibility, prognosis and therapy outcome. The purpose of this study was to investigate the correlation of ERCC1 and XRCC1 polymorphisms with colorectal cancer (CRC) risk, and explore the effect of polymorphisms on event-free, overall survival and oxaliplatin-based therapy in CRC patients. Genotyping was examined with the iMLDR technique. An unconditional logistic regression model was used to estimate the association of certain polymorphisms with CRC risk. The Kaplan-Meier method, log-rank test and Cox regression model were employed to evaluate the effects of polymorphisms on survival analysis. Results showed that Trp/Trp genotype of XRCC1 Arg194Trp and AA genotype of ERCC1 rs2336219 have a significantly increased risk of CRC; Trp allele of XRCC1 Arg194Trp and CC genotype of ERCC1 rs735482 were associated with lower response to oxaliplatin-based chemotherapy, a shorter survival and a higher risk of relapse or metastasis. 194Trp/280Arg/399Arg haplotype was associated with a significant resistance, and the ERCC1 protein expression was statistically higher in tumours with rs735482 CC genotype than with AA genotype. Our studies indicate that XRCC1 and ERCC1 polymorphisms probably affect susceptibility, chemotherapy response and survival of CRC patients.