These data suggest that the XRCC1Arg399Gln polymorphism is associated with an increased risk of developing HNC, because it correlates with occupational exposure in Tunisian population.
The XRCC1Arg194Trp polymorphism was significantly associated with HNC risk in studies that were adjusted for smoking and alcohol under the homozygous and heterozygote models.
Overall, no evidence of significant association was observed between XRCC1 Arg194Trp, XRCC1Arg280His, XRCC1Arg399Gln genotypes and the risk of HNC in any genetic models.
In this study, we have found that the deregulation of BER genes (XRCC1 and OGG1) in relation to excessive proliferation (as measured by proliferation marker Ki-67) may be considered as important factors in the development of head and neck cancer in Pakistani population.
Marginally statistically significant association was found for XRCC1 codon 399 (for Caucasians only), XPD Asp312Asn and XRCC1 codon 194 variants and head and neck cancer.
Because of the important role of the XRCC1 gene in DNA repair, we wanted to test the effects of the Arg194Trp and Arg399Gln polymorphisms of XRCC1 on the clinical outcome of head and neck cancer.
Polymorphisms of XRCC1, FGFR, and CCND1 have been consistently associated with HNC survival in at least two studies, whereas most of the other polymorphisms have either conflicting data or were from single studies.
Pooling data and DNA specimens from three case-control studies in western Washington State, North Carolina, and Puerto Rico, totaling 555 cases (430 whites) and 792 controls (695 whites), we studied the risk of head and neck cancer in relation to common nonsynonymous single-nucleotide polymorphisms in four DNA repair genes: MGMT (Leu84Phe and Ile143Val), XRCC1 (Arg399Gln), XPD (Lys751Gln), and XRCC3 (Thr241Met).