Gene-gene interaction analysis showed that subjects carrying ERCC1 rs11615 C allele and XPG/ERCC5 rs17655 G allele had a greatly increased risk of breast cancer.
Overall, no significantly elevated breast cancer risk was found in all genetic models when all studies were pooled into the meta-analysis (for XPG Asp1104His Asp/His vs. Asp/Asp: OR 1.02, 95% CI 0.94-1.11; His/His vs. Asp/Asp: OR 0.96, 95% CI 0.83-1.11; dominant model: OR 1.01, 95% CI 0.94-1.09; and for XPF Arg415Gln Arg/Gln vs. Arg/Arg: OR 1.00, 95% CI 0.89-1.12; Gln/Gln vs. Arg/Arg: OR 2.40, 95% CI 0.62-9.22; dominant model: OR 1.03, 95% CI 0.90-1.18).
Genotyping of polymorphisms of XRCC1 (Arg194Trp and Arg399Gln), OGG1 (Ser326Cys and Arg229Gln), ERCC2 Lys751Gln, ERCC4 Ser662Pro, and ERCC5 His1104Asp was performed and used to evaluate breast cancer susceptibility.
Of the 6 ERCC variants examined, only ERCC5 rs1</span>7655 showed a borderline main effect association with breast cancer risk (OR(GC) = 1.1, OR(CC) = 1.3; p-trend = 0.08), with some indication that individuals carrying the C allele variant were more susceptible to the effects of occupational radiation (EOR/Gy(GG) = 1.0, 95% CI = <0, 6.0; EOR/Gy(GC/CC) = 5.9, 95% CI = 0.9, 14.4; p(het) = 0.10).
Using data/samples collected from the first 752 Caucasians and 141 African-Americans in an ongoing case-control study, we examined the association between breast cancer risk and 18 non-synonymous single-nucleotide polymorphisms (nsSNPs) in four DNA repair pathways-(i) base excision repair: ADPRT V762A, APE1 D148E, XRCC1 R194W/R280H/R399Q and POLD1 R119H; (ii) nucleotide excision repair: ERCC2 D312N/K751Q, ERCC4 R415Q, ERCC5 D1104H and XPC A499V/K939Q; (iii) mismatch repair: MLH1 I219V, MSH3 R940Q/T1036A and MSH6 G39E and (iv) double-strand break repair: NBS1 E185Q and XRCC3 T241M.