Association of DNA repair gene polymorphisms with response to platinum-based doublet chemotherapy in patients with non-small-cell lung cancer

Purpose: To identify polymorphisms in DNA repair genes that affect responses to platinum-based doublet chemotherapy in patients with non-small-cell lung cancer (NSCLC). Patients and Methods: In total, 640 patients with NSCLC who received platinum-based doublet chemotherapy in the National Cancer Center Hospital in Japan from 2000 to 2008 and whose responses were evaluated by Response Evaluation Criteria in Solid Tumors (RECIST) participated in a study of the association between response and genotypes for 30 single nucleotide polymorphisms (SNPs) in 27 DNA repair genes. Candidate SNPs were selected in a discovery set of 201 patients, and their associations were validated in an independent set of 439 patients by prespecified P value criteria. Results: Homozygotes for the minor allele TP53-72Pro of the Arg72Pro SNP in the TP53 gene showed a better response rate (54.3%) than those for the major allele TP53-72Arg (29.1%; P=4.4×10^-5) irrespective of therapeutic regimens, and minor allele homozygotes had significantly longer progression-free and overall survivals than major allele homozygotes (hazard ratio [HR], 0.85; 95% CI, 0.74 to 0.98; P=.020; and HR, 0.86; 95% CI, 0.74 to 0.99; P = .039). Minor allele carriers for SNP Lys940Arg in the poly (ADP-ribose) polymerase 1 (PARP1) gene showed a better response rate to the paclitaxel regimen (45.8%) than to the gemcitabine regimen (10.5%; P for interaction = .019). Conclusion: Polymorphisms in the TP53 and PARP1 genes are involved in inter-individual differences in the response to platinum-based doublet chemotherapy in patients with NSCLC.