title: XPD/ERCC2 polymorphisms and risk of head and neck cancer: a case-control analysis.
abstract: DNA repair capacity is central in maintaining normal cellular functions. Variants of several DNA repair genes,including the nucleotide excision repair gene XPD, have been described recently. Because we previously reported that patients with squamous cell carcinoma of the head and neck (SCCHN) had lower DNA repair capacity than healthy controls, we hypothesized that inherited polymorphisms of XPD may contribute to genetic susceptibility to SCCHN, a tobacco-related cancer. To test this hypothesis, we conducted a hospital-based case-control study of 189 SCCHN patients and 496 cancer-free controls who were frequency-matched on age, gender and smoking status. All subjects were non-Hispanic whites. Two XPD polymorphisms (C22541A and A35931C) were typed using the restriction enzymes TfiI and PstI, respectively. Multivariate logistic regression analysis was performed to calculate adjusted odds ratios (ORs) and 95% confidence intervals (CIs). In the controls, the frequencies of the variant 22541A and 35931C alleles were 44.7% and 33.8%, respectively. The frequency of the 22541A homozygous genotype (22541AA) was lower in cases (15.9%) than in controls (20.4%) but was not associated with risk (adjusted OR = 0.90; 95% CI = 0.52-1. 56) for SCCHN. The frequency of the 35931C homozygous genotype (35931CC) was higher in cases (16.4%) than in controls (11.5%) and associated with a borderline increased risk (adjusted OR = 1.55; 95% CI = 0.96-2.52) for SCCHN. The risk was higher in older subjects (OR = 2.22; 95% CI = 1.03-4.80), current smokers (OR = 1.83; 95% CI = 0.79-4.27) and current drinkers (OR = 2.59; 95% CI = 1.25-5.34) in the stratification analysis. These results suggest a gene-environment interaction, but this did not reach statistical significance. The findings are limited due to the relatively small numbers in the subgroups and need to be verified by further investigations.
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: R
authors.initials: R
authors.lastname: Zheng
authors.forename: L
authors.initials: L
authors.lastname: Li
authors.forename: E J
authors.initials: EJ
authors.lastname: Castillo
authors.forename: S A
authors.initials: SA
authors.lastname: Eicher
authors.forename: M
authors.initials: M
authors.lastname: Chen
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: D000328:Adult; D000368:Aged; D000428:Alcohol Drinking; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000235:genetics*; D016022:Case-Control Studies; D004265:DNA Helicases / Q000235:genetics; D004268:DNA-Binding Proteins; D005260:Female; D020022:Genetic Predisposition to Disease; D005838:Genotype; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000235:genetics*; D006720:Homozygote; D006801:Humans; D008297:Male; D008875:Middle Aged; D011110:Polymorphism, Genetic; D011506:Proteins / Q000235:genetics*; D012307:Risk Factors; D012907:Smoking; D014157:Transcription Factors; D051759:Xeroderma Pigmentosum Group D Protein
chemical_list: D004268:DNA-Binding Proteins; D011506:Proteins; D014157:Transcription Factors; D004265:DNA Helicases; D051759:Xeroderma Pigmentosum Group D Protein; C497292:ERCC2 protein, human