Men with the p53 codon 72 Pro/Pro genotype appear to be at reduced risk of prostate cancer.

Although the thermolabile MTHFR mutation is very common, it does not appear to be a significant genetic risk factor for typical late-onset vascular disease. Because MTHFR homozygotes have increased homocysteine with low folate levels, this mutation may contribute to early-onset or familial vascular disease. The genotype dependence of the folate-homocysteine correlation further suggests that homozygotes for this mutation may have both an exaggerated hyperhomocysteinemic response to folic acid depletion and a better response to folic acid therapy.

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Background. Glutathione S-transferase T1 detoxifies some environmental carcinogens while activating others and is deleted in 15% to 38% of humans. We sought to determine whether GSTT1 genotype and genotypes of several related genes are associated with risk of squamous cell carcinoma of the head and neck (HNSCC).Methods. Somatic genotypes for GSTT1, GSTM1, GSTP1, and CYP1A1 were determined in 283 individuals with HNSCC and 208 population-based controls.Results. The OR for presence of GSTT1 was 1.6 (CI, 1.1 -2.5, p = .03). HNSCC risk was not associated with GSTM1 null genotype, the presence of the GSTP1 Val/Val genotype, or the Val/Val homozygous genotype for CYP1A1. Stratified analysis revealed disparate ORs for women (OR, 3.0; CI, 1.5 -6.3) and men (OR, 1.2; CI, 0.7 -2.1) for the presence of GSTT1.Conclusions. In this population, the presence of GSTT1 gene was associated with a significant increase in the risk of HNSCC.This association was particularly robust in women. B

Objective To assess whether genetic polymorphisms implicated as risk factors for other tobacco‐associated malignancies are associated with altered risk of head and neck squamous cell carcinoma. Design Case‐control study. Subjects One hundred sixty patients with head and neck squamous cell carcinoma recruited from a university‐based head and neck oncology clinic and 149 population‐based controls. Methods Genotyping of the CYP1A1 (Ile462Val), GSTM1 (null), GSTP1 (Ile105Val), GSTT1 (null), and P53 (Arg72Pro) genes was performed by polymerase chain reaction–based techniques on DNA prepared from peripheral blood. In addition, a questionnaire was used to collect demographic information from each subject. Results Cases were significantly older (p < .0001) and had significantly greater tobacco use (p < .0001) and were more likely to be male (p < .0001) than were control subjects, thus confirming known risk factors for this disease. When cases and controls were compared by simple chi‐square analysis, only the frequency of CYP1A1 (Ile462Val) polymorphism was significantly different between cases and controls (OR = .42; 95% CI = .18–.99; p < .04). However, with a logistic regression model to control for known risk factors, we were unable to demonstrate a significant association with head and neck cancer for any of the polymorphisms tested, including CYP1A1. Conclusions This population fails to identify a relationship between the above‐mentioned polymorphisms and head and neck cancer. © 2000 John Wiley & Sons, Inc. Head Neck 22: 609–617, 2000.