Early Detection of Oral Cancer by an Optical Measurement System Measuring Autofluorescence

Abstract

Oral squamous cell carcinoma (OSCC) has been a focus of cancer prevention studies due to the fact that it occurs by a multistep process and that a precancerous lesion in the oral mucosa is easily accessible. The present study was aimed at developing an optical detection system using autofluorescence spectrum measurements for the early detection of oral cancer. The optical detection system was designed to use an excitation wavelength of 337 nm emanating from a Xenon lamp. Precancerous and cancerous lesions were created in the hamster buccal pouch by treatment with 7,12 - dimethylbenz[a]anthracene (DMBA). Four groups of five hamsters each were used in this experiment. The right buccal pouch was treated with 0.5% DMBA to induce carcinogenesis while the left buccal pouch was treated with mineral oil as a control. The autofluorescence of both buccal pouches was measured weekly. A difference in the excitation pattern between the normal and the carcinogen - treated tissue was noticed after three weeks. Specifically, the intensity of the autofluorescence spectrum in the DMBA - treated buccal pouch was increased at wavelengths between 400 and 450 nm. The results of the autofluorescence measurements were compared to histological findings and show that the intensity of the autofluorescence increased along with the stage of epithelial dysplasia. Based on the fact that one of the autofluorophores in this tissue is NADH, we measured the fluorescence at the 450-nm NADH wavelength to conclude that the increased autofluorescence in the dysplastic areas may be caused by NADH. Based on these data, we suggest that autofluorescence optical methods are a useful tool for the early detection of oral cancer