An intronic poly (AT) polymorphism of the DNA repair gene XPC and risk of squamous cell carcinoma of the head and neck: A case-control study

Inherited polymorphisms of DNA repair genes may contribute to variations in DNA repair capacity and genetic susceptibility to cancer. In a hospital-ba sed case-control study of 287 non-Hispanic white patients with newly diagno sed SCCHN and 311 control subjects matched on age, sex, ethnicity, and smok ing status, we investigated the role of a newly identified variant allele o f XPC, XPC-PAT+. We found that the frequency of the XPC-PAT+ allele was hig her in the cases (0.409) than in the controls (0.333; P = 0.007). Fifty cas es (17.4%) and 37 controls (11.9%) were XPC-PAT+/+, and 135 (47.0%) cases a nd 133 controls (42.8%) were XPC-PAT+/-, XPC-PAT+/- and XPC-PAT+/+ subjects were at significantly increased risk for SCCHN [adjusted odds ratios = 1.4 4 and 1.85, respectively (95% confidence intervals, 1.01-2.05 and 1.12-3.05 , respectively; trend test, P = 0,007)]. We did not find ethnic difference in the frequency of XPC-PAT+ allele among four groups aged between 19 and 7 5 years: non-Hispanic whites, 294; African-Americans, 178; Hispanic-America ns, 103; and native Chinese, 119 (0.333, 0.281, 0.296, and 0.353, respectiv ely), The case-control findings support the hypothesis that the XPC-PAT+ al lele may contribute to the risk of developing SCCHN.