Role of NQO1 polymorphisms as risk factors for squamous cell carcinoma of the head and neck

A case:control study was carried out to determine if inactivating polymorphisms of the NQO1 gene at bases 609 and 465 are associated with altered risk of developing squamous cell carcinoma of the head and neck (SCCHN). Genotyping was carried out by PCR RFLP analysis on whole blood samples. The frequency of the inactive ⁶⁰⁹T and active ⁶⁰⁹C forms, and the inactive ⁴⁶⁵T and active ⁴⁶⁵C forms, of NQO1 were compared in patient and control groups by a logistic regression analysis and odds ratios (ORs) were calculated. Participants were stratified by tobacco and alcohol use, and genotype distributions in these sub-groups were compared. There were no significant differences in genotype distribution between SCCHN patients and the control population for the base 609 or 465 polymorphisms. There were also no significant differences in genotype distributions between patient and control groups for tobacco and/or alcohol users and non-users. Genotype distributions were similar for SCCHN patients at all disease sites with the exception of the nasopharynx where there was a higher incidence of the ⁶⁰⁹C:⁶⁰⁹T and ⁶⁰⁹T:⁶⁰⁹T genotypes. These results suggest that individuals having either ⁶⁰⁹T or ⁴⁶⁵T alleles generally do not have an altered risk of developing SCCHN.