Gamma-glutamyl transpeptidase activity in human oral squamous cell carcinoma.

Gamma-glutamyl transpeptidase (GGT) activity has been shown to increase in preneoplastic cells in various experimental carcinogenesis models and in some human tumors. This pilot study was undertaken to examine its potential use in detection of sites of human oral carcinogenesis. Samples were taken from 16 surgical specimens: 12 resection specimens for squamous carcinomas and 4 benign mucosal lesions. Twelve of the patients were tobacco users. Diffuse GGT activity was found in all tobacco users and heavy cellular activity in all carcinomas. In four of the carcinoma-resection specimens, occasional cells staining heavily for GGT activity were noted in epithelium distant from the tumor itself. These results are discussed in relation to the potential value of GGT activity as a marker from preneoplastic changes in oral epithelium.