RESUMO
BACKGROUND: Alcohol intake and tobacco smoke, in addition to other environmental and genetic factors, have been associated with head and neck cancer. We evaluated the role of metabolic enzyme polymorphisms on the risk of head and neck cancer in a hospital-based case-control study. METHODS: CYP1A1MspI, CYP2E1PstI, GSTM1, and GSTT1polymorphisms were evaluated in 103 histologically confirmed head and neck cancer cases and 102 controls by means of polymerase chain reaction-restriction fragment length polymorphism methods. RESULTS: GSTM1null increased the risk of head and neck cancer (odds ratio [OR], 2.2; 95% confidence interval [95% CI], 1.24-3.79), oral cancer (OR, 2.8; 95% CI, 1.28-5.98), and pharyngeal cancer (OR, 2.2; 95% CI, 1.08-4.63). CYP2E1PstI polymorphism indicated a risk for oral cancer (OR, 3.6; 95% CI, 1.29-11.56). The joint effect of GSTM1 null and CYP1A1 polymorphism increased the risk of head and neck cancer (OR, 2.4; 95% CI, 1.13-5.10). CONCLUSIONS: GSTM1 null alone or associated with CYP1A1 increased the risk of head and neck cancer; the CYP2E1PstI mutated allele increased the risk for only oral cancer.
