['The goals of this study were to determine if single-nucleotide polymorphisms in DNA damage repair genes and cell cycle regulating genes affect clinical response to combined gemcitabine radiation therapy and the overall survival (OS) of patients with pancreatic cancer.', 'We evaluated six single-nucleotide polymorphisms of the ATM, ATM and Rad3-related (ATR), CHEK1, and CHEK2 genes in 119 patients with potentially resectable pancreatic cancer who were enrolled in clinical trials at The University of Texas M. D. Anderson Cancer Center from February 1999 to January 2006, with follow-up until February 2007. Patients received neoadjuvant concurrent gemcitabine and radiation therapy with or without gemcitabine-cisplatin induction therapy. Genotypes were determined and tested for associations with OS by Kaplan-Meier estimation, the log-rank test, and Cox regression analysis. P values of <or=0.05 were considered significant.', 'The ATM G60A and CHEK1 G35A genotypes were significant (P<0.05), and the ATR C340T genotype borderline significantly (P=0.079) associated with OS. The hazard ratio of CHEK1 35AA was 2.01 (95% confidence interval, 1.20-3.37; P=0.007) compared with CHEK1 35GG/GA with adjustments for race, sex, diabetes status, CA19-9 level, and success of tumor resection. A significant combined genotype effect was observed between ATM 60GA/GG, ATR 340CT/CC, and CHEK1 35AA with median OS times of 31.0, 16.2, and 10.5 months for patients carrying <or=1, 2, and 3 deleterious alleles, respectively (P=0.004).'] Are single-nucleotide polymorphisms of DNA damage response genes associated with overall survival in patients with pancreatic cancer?