In conclusion, the APE1Asp148Glu polymorphism is highly predictive for lung cancer, and cumulative cigarette smoking modifies the associations between the XRCC1 Arg399Gln and the XPD Lys751Gln polymorphisms and lung cancer risk.
We identified a sufficient number of epidemiologic studies on lung cancer to conduct a meta-analysis for genetic polymorphisms in nucleotide base repair (BER) pathway, focusing on 8-oxoguanine DNA glycosylase 1, X-ray cross-complementing group 1 (XRCC1) and apurinic/apyrimidinic endonuclease 1.
A common APE1 polymorphism, a T-->G transversion (Asp 148 Glu), was previously shown to be associated with risk of lung cancer, an association that was modified by cigarette smoking.
These results suggest that APE1Asp148Glu and XRCC1 Arg399Gln polymorphisms might modify the risk of lung cancer attributable to cigarette smoking exposure.
Combinations of polymorphisms in genes involved in the same repair pathway (XPA + XPD or XRCC1 + APE1) affected lung cancer risk only in patients with SCC.