The genetic variations in DNA repair genes ERCC2 and XRCC1 were associated with the overall survival of advanced non‐small‐cell lung cancer patients

It was reported that DNA repair can confer cancer cell resistance to therapeutic treatments by activating antiapoptotic cellular defense. We hypothesized that genetic variants of DNA repair genes may be associated with lung cancer prognosis. Seventeen tagging single-nucleotide polymorphism (tagSNPs) selected from 12 DNA repair genes were genotyped in 280 advanced non-small-cell lung cancer (NSCLC) patients by TaqMan assay. The associations of these SNPs and overall survival of advanced NSCLC patients were investigated. Advanced NSCLC patients carrying ERCC2 rs50872 CT+TT genotypes had significantly longer median survival time (MST) and decreased death risk than patients with rs50872 CC genotype [log-rank P = 0.031; adjusted HR(95% CI) = 0.73 (0.55-0.98), P = 0.033]. These effects were mainly seen among younger patients (≤65 years old) [HR(95% CI) = 0.57 (0.37-0.87), P = 0.010], patients without surgery [HR(95% CI) = 0.68 (0.47-0.98), P = 0.036] but with chemotherapy [HR(95% CI) = 0.64 (0.46-0.91), P = 0.012] or radiotherapy [HR(95% CI) = 0.58 (0.38-0.89), P = 0.013]. Meanwhile, compared to advanced NSCLC patients with rs25487 GG genotype, patients carrying XRCC1 rs25487 GA+AA genotypes had significantly shorter MST (MST = 11.7 vs. 16.7, log-rank P = 0.048). In addition, advanced NSCLC patients carrying the ERCC2 rs50872 CC in combination with XRCC1 rs25487 GA+AA genotype had the shortest MST (11.2 month) and highest death risk [HR(95% CI) = 1.70 (1.15-2.52), P = 0.008] when compared with those carrying rs50872 CT+TT and rs25487 GG genotype (MST = 22.0 month). The ERCC2 rs50872 T allele was associated with favorable but XRCC1 rs25487 A allele with bad survival for advanced NSCLC in Chinese population, which may offer novel biomarkers for predicting clinical outcomes.