Cortisone and hamster buccal pouch carcinogenesis.

Ninety male Syrian hamsters, 3 months of age, were divided into 6 equal experimental groups of 15 animals. Two groups served as controls for 8and 16-week experimental periods. In the remaining 4 groups, the light buccal pouch was painted 3 times weekly with 9,10-dimethyl-l ,2-benzanthracene (DMBA) and sacrificed at 8 and 16 weeks. One 8-week and one 16-week experimental group were also injected 3 times weekly with 2.0 mg of cortisone acetate. It was found that in those animals receiving cortisone as well as DMBA applications, the development of initial dysplasia and of buccal |x>uch carcinomas was hastened. Although the tumors induced in the cortisone-DMBA animals were histologioally not more anaplastic than those in the DMBA animals, invasion of underlying connective tissue and muscle was more extensive and the tumors were considerably larger in size. Metastasis to regional lymph nodes was not observed in any of the groups.