Polymorphisms in genes of APE1, PARP1, and XRCC1: risk and prognosis of colorectal cancer in a Northeast Chinese population

Base excision repair (BER) pathway plays critical role in maintaining genome integrity. Polymorphisms in BER genes which modulate the DNA repair capacity may affect the susceptibility and prognosis of cancer. We conducted a case-control study and followed up the cases to explore the associations between BER genes polymorphisms and the risk and prognosis of colorectal cancer (CRC). This study included 451 CRC patients and 631 controls. Four single-nucleotide polymorphisms (SNPs) in genes of apurinic/apyrimidinic endonuclease-1 (APE1), ADP-ribosyltransferase (ADPRT, also known as PARP1), and X-ray repair cross-complementing groups 1 (XRCC1) were tested by PCR-RFLP. Odds ratio (OR), hazard ratio (HR), and their 95 % confidence intervals (CIs) were calculated by unconditional logistic regression and Cox proportional hazard model. PARP1 762 recessive model (OR = 1.57, 95 % CI 1.12-2.20) and XRCC1 194 dominant model (OR = 1.45, 95 % CI 1.12-1.88) were associated with increased CRC risk. A significant increasing trend for the risk of CRC was detected with the increasing number of putative risk genotypes (P-trend = 0.00). However, no association was found between these four SNPs and the prognosis of CRC. In conclusion, APE1 (Asp148Glu), PARP1 (Ala762Val), and XRCC1 (Arg399Gln, Arg194Trp) were associated with the susceptibility to CRC, but were not associated with the prognosis of CRC.