The association of APE1 −656T > G and 1349 T > G polymorphisms and cancer risk: a meta-analysis based on 37 case-control studies

BACKGROUND: APE1 (apurinic/apyrimidinic endonuclease 1) is an important DNA repair protein in the base excision repair pathway. Polymorphisms in APE1 have been implicated in susceptibility to cancer; however, results from the published studies remained inconclusive. The objective of this study was to conduct a meta-analysis investigating the association between polymorphisms in APE1 and the risk for cancer. METHODS: The PubMed and Embase databases were searched for case-control studies published up to June, 2011 that investigated APE1 polymorphisms and cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. RESULTS: Two polymorphisms (−656 T > G, rs1760944 and 1349 T > G, rs1130409) in 37 case-control studies including 15, 544 cancer cases and 21, 109 controls were analyzed. Overall, variant genotypes (GG and TG/GG) of −656 T > G polymorphism were associated with significantly decreased cancer risk in homozygote comparison (OR = 0.81, 95%CI: 0.67-0.97), dominant model comparison (OR = 0.89, 95%CI: 0.81-0.97) and recessive model comparison (OR = 0.90, 95%CI: 0.82-0.98), whereas the 1349 T > G polymorphism had no effects on overall cancer risk. In the stratified analyses for −656 T > G polymorphism, there was a significantly decreased risk of lung cancer and among Asian populations. CONCLUSIONS: Although some modest bias could not be eliminated, the meta-analysis suggests that APE1 −656 T > G polymorphism has a possible protective effect on cancer risk particularly among Asian populations whereas 1349 T > G polymorphism does not contribute to the development of cancer.