Genetic Polymorphisms In DNA Repair Genes And Risks Of Laryngeal & Hypopharyngeal Carcinomas

Background & Aim: XRCCl (X-ray repair cross complementary 1) plays an important role in base excision repair (BER). This study sought to examine the relationship between single nucleotide polymorphisms (SNPs) in XRCCl and the risk of developing laryngeal carcinoma and hypopharyngeal carcinoma.Methods: Genotypes were determined in 175 patients with laryngeal carcinoma or hypopharyngeal carcinoma and 525 controls by polymerase chain reaction-based restriction fragment length polymorphism (PCR-RFLP). The odds ratio (OR) and 95% confidence interval (CI) were estimated by logistic regression.Results: The distribution of genotypes of 3 XRCC1 genetic variants in cases and controls was consistent with Hardy-Weinberg equilibrium.It was found that the XRCCl polymorphisms in Arg194Trp and Arg399Gln were not associated with the risk of laryngeal carcinoma and hypopharyngeal carcinoma. The XRCCl 280His allele increased the risk of developing laryngeal carcinoma and hypopharyngeal carcinoma. The subjects at least having one XRCC 1 280His had an OR of 1.69 (95% CI 1.11-2.56) comparing with noncarriers.Respectively analyzing the risks of laryngeal carcinoma and hypopharyngeal carcinoma, the XRCCl Argl94Trp and Arg399Gln were neither associated with the risk of laryngeal carcinoma nor the risk of hypopharygeal carcinoma. It was the risk of laryngeal carcinoma but not risk of hypopharyngeal carcinoma that the allele XRCCl 280His increased. The subjects with laryngeal carcinoma at least having one XRCCl 280 His had an OR of 1.70 (95% CI 1.07-2.71) compared with noncarriers.Smoking increased the risk of developing laryngeal carcinoma and hypopharyngeal carcinoma, having an OR of 3.81 (95% CI 2.32-6.30). The interaction of smoking and XRCCl Arg280His polymorphism increased risk of laryngeal carcinoma...