Effects of prednisolone and thalidomide on induced submandibular gland tumors in hamsters.

No significant difference in the incidence of induced fibrosarcomas in hamster submandibular glands was noted when the animals were given a single intraglandular injection of 100, 200, 500, and 1000 jug of prednisolone concurrently with adminis tration of 0.05 ml of 0.5% 7:12-dimethylbenz(a)anthracene (DMBA) in liquid petrolatum. There was, however, an inhibi tory trend when, in addition to the initial intraglandular injec tion of 500 jug of prednisolone, the same amount was injected i.p. every week throughout the experiment. There was a higher but insignificant incidence of metastasis in prednisolone-treated hamsters as compared to the controls. Thalidomide failed to show any influence on induced tumors when given to hamsters in a similar procedure using 3 dosage levels, a single 5or 10-mg dose, and a 5-mg initial injection plus 5 mg/week.