Studies on the carcinogenic action of dimethylsulfoxide extracts of betel nut in the hamster bucal pouch

Abstract

This is a report on the results of eight experiments specifically designed to study the effects of topical application of a dimethylsulfoxide extract of betel nut on the mucosa of the hamster buccal pouch. Various adjuvants, tobacco, hexestrol and azathioprine were employed in these experiments to enhance the animals' susceptibility to tumor formation. Of the adjuvants employed, only one, tobacco, resulted in the development of squamous cell carcinoma by itself; yet when combined with betel nut, no tumors developed. None of the other adjuvants were by themselves, or in combination with betel nut, capable of inducing any change in the oral mucosa of the golden Syrian hamster. During the course of this study, there were three unusual findings: (1) a diagnosed case of malignant lymphoma in the cheek pouch of one animal treated with a known carcinogen; (2) a diagnosed case of a rhabdomyosarcoma at the site of injection of an immunosuppressant; and (3) the development of perioral tumors in 15 percent of the treated animals.