title: XRCC1, XRCC3, and XPD polymorphisms as modifiers of the effect of smoking and alcohol on colorectal adenoma risk.
abstract: Using a sigmoidoscopy-based case-control study (753 cases, 799 controls) in Los Angeles County, we investigated the potential modifier role in the effect of alcohol and smoking of single-nucleotide polymorphisms (SNP) in three DNA repair genes, XRCC1 (Arg194Trp and Arg399Gln), XRCC3 (Thr241Met), and XPD (Lys751Gln). We have previously reported an inverse association between the XRCC1 codon 399 SNP and adenoma risk among these subjects. We now report that subjects with the XPD Gln/Gln genotype were inversely associated with adenoma risk [odds ratio (OR), 0.7; 95% confidence interval (95% CI), 0.5-1.0] when compared with subjects with the Lys/Lys and Lys/Gln genotypes combined. This association differed between different ethnic groups (gene x race heterogeneity likelihood ratio test, P = 0.009), with a stronger inverse association among Latinos (OR, 0.1; 95% CI, 0.01-0.5) than among non-Latinos (OR, 0.9; 95% CI, 0.-1.3). We found no evidence of an XRCC3 x smoking or alcohol interaction or an XRCC1 x alcohol interaction. Instead, our data supported an XRCC1 x smoking interaction (P = 0.048). Whereas XPD did not modify the effect of smoking, our data suggested an XPD x alcohol interaction. Analyses ignoring XPD showed no association between alcohol intake and adenoma prevalence; however, among carriers of the codon 751 Gln/Gln genotype, we found a significant positive association (OR, 2.5; 95% CI, 1.2-5.2 for ever drinkers; test of interaction P = 0.04). Our data suggest that the effects of smoking and alcohol may vary depending on the genetic background of proteins that participate in the base excision repair and nucleotide excision repair pathways.
authors.affiliation: University of Southern California/Norris Comprehensive Cancer Center, Keck School of Medicine, 1441 Eastlake Avenue, room 5421A, Los Angeles, CA 90089, USA. stern_m@ccnt.hsc.usc.edu
authors.forename: Mariana C
authors.initials: MC
authors.lastname: Stern
authors.forename: Kimberly D
authors.initials: KD
authors.lastname: Siegmund
authors.forename: David V
authors.initials: DV
authors.lastname: Conti
authors.forename: Román
authors.initials: R
authors.lastname: Corral
authors.forename: Robert W
authors.initials: RW
authors.lastname: Haile
mesh_terms: D000236:Adenoma / Q000453:epidemiology / Q000235:genetics*; D000368:Aged; D000428:Alcohol Drinking / Q000235:genetics*; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016001:Confidence Intervals; D004260:DNA Repair / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000235:genetics*; D005260:Female; D006801:Humans; D015141:Los Angeles / Q000453:epidemiology; D008297:Male; D008875:Middle Aged; D020641:Polymorphism, Single Nucleotide; D012307:Risk Factors; D012907:Smoking / Q000235:genetics*; D000076105:X-ray Repair Cross Complementing Protein 1; D051759:Xeroderma Pigmentosum Group D Protein / Q000235:genetics*
chemical_list: D004268:DNA-Binding Proteins; D000076105:X-ray Repair Cross Complementing Protein 1; C110901:X-ray repair cross complementing protein 3; C000619371:XRCC1 protein, human; D051759:Xeroderma Pigmentosum Group D Protein