title: Polymorphisms of DNA repair gene XRCC1 in squamous cell carcinoma of the head and neck.
abstract: Because reduced DNA repair capacity (phenotype) has been suggested as a risk factor for squamous cell carcinoma of the head and neck (SCCHN), newly-identified DNA repair gene polymorphisms (genotype) may also be implicated in risk. To test this hypothesis, we conducted a case-control study of 203 SCCHN patients and 424 control subjects (matched for age, sex and ethnicity) to investigate the role of two XRCC1 polymorphisms (XRCC1 26304 T and XRCC1 28152 A, respectively) in SCCHN. Multivariate logistic regression analysis was performed to calculate the adjusted odds ratio (OR) and 95% confidence interval (CI). A total of 180 cases (88.7%) and 363 controls (85.6%) lacked the XRCC1 26304 T allele [adjusted OR = 1.34 (CI, 0.80-2.25)]. Lack of this polymorphism was a significant risk factor specifically for cancers of the oral cavity and pharynx [adjusted OR = 2.46 (CI, 1.22-4.97)]. Thirty-two cases (15.8%) and 46 controls (10.8%) were homozygous for the XRCC1 28152 A allele [adjusted OR = 1.59 (CI, 0.97-2.61) for all cases, and 1.41 (CI, 0. 80-2.48) for oral and pharyngeal cancer only]. Furthermore, when the two genotypes were combined into a three-level model of risk, a polymorphism-polymorphism interaction of increasing risk (trend test, P = 0.049) was evident: OR = 1.0 for those with neither risk genotype (referent group), adjusted OR = 1.51 (CI, 0.87-2.61) for those with either risk genotype, and 2.02 (CI, 1.00-4.05) for those with both risk genotypes. For oral and pharyngeal cancer, this trend was even more pronounced with the adjusted OR = 2.68 (CI, 1.28-5.61) for those with either risk genotype, and 3.22 (CI, 1.33-7.81) for those with both risk genotypes. The findings support the hypothesis that a polymorphic XRCC1 DNA repair gene contributes to risk of developing SCCHN.
authors.affiliation: Department of Head and Neck Surgery, The University of Texas-M.D.Anderson Cancer Center, Houston, TX 77030, USA.
authors.forename: E M
authors.initials: EM
authors.lastname: Sturgis
authors.forename: E J
authors.initials: EJ
authors.lastname: Castillo
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: R
authors.initials: R
authors.lastname: Zheng
authors.forename: S A
authors.initials: SA
authors.lastname: Eicher
authors.forename: G L
authors.initials: GL
authors.lastname: Clayman
authors.forename: S S
authors.initials: SS
authors.lastname: Strom
authors.forename: M R
authors.initials: MR
authors.lastname: Spitz
authors.forename: Q
authors.initials: Q
authors.lastname: Wei
mesh_terms: D001483:Base Sequence; D002294:Carcinoma, Squamous Cell / Q000235:genetics*; D017931:DNA Primers; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D020022:Genetic Predisposition to Disease; D006258:Head and Neck Neoplasms / Q000235:genetics*; D006801:Humans; D011110:Polymorphism, Genetic; D000076105:X-ray Repair Cross Complementing Protein 1
chemical_list: D017931:DNA Primers; D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C000619371:XRCC1 protein, human