GLUTATHIONE-S-TRANSFERASE GENOTYPES AS RISK-FACTORS FOR HEAD AND NECK-CANCER

BACKGROUND: Several enzymatic systems, including glutathione S-transfe rases, are involved in the metabolism of environmental agents, The abs ence of glutathione S-transferases mu (GSTM1) and theta (GSTT1) result s in decreased detoxification of carcinogens, for example, chemicals i n cigarette smoke,;These metabolic deficiencies may predispose individ uals to the development of smoking-related tumors, such as cancers of the lung, head and neck, and bladder. METHODS: The glutathione S-trans ferase genotypes of 186 previously untreated patients with squamous ce ll carcinoma of the head and neck and 42 healthy controls were determi ned with polymerase chain reaction (PCR) methodologies, Lymphocytes se parated from heparinized peripheral blood or whole blood extracts serv ed as sources of genomic DNA, The presence or absence of the gene-spec ific PCR products revealed the positive or negative genotypes, respect ively. RESULTS: The absence of the GSTM1 genotype conferred an odds ra tio of 2.37, and the 95% confidence interval (Cl) was 1.20 to 4.67. Th e absence of the GSTT1 gene conferred an odds ratio of 1.47 (Cl 0.71 t o 3.02). In the population of 42 patients and their matched 42 control s, the absence of the GSTM1 and GSTT1 genotypes conferred odds ratios of 3.10 (Cl 1.24 to 7.75) and 2.18 (Cl 0.91 to 5.23), respectively. CO NCLUSIONS: Despite the small study size, our preliminary data suggest that genetically determined factors of carcinogen metabolism may be as sociated with increased risk for head and neck cancer.