Immunotherapy of Chemically-Induced Tumors in the Hamster Cheek Pouch with Dinitrochlorobenzene

Immune stimulation with an agent such as di-nitrochlorobenzene (DNCB) may delay chem-cal carcinogenesis. Dimethylbenzanthracene (DMBA) was used to chemically induce tu-mors in the hamster buccal pouch. Hamsters were studied for the effect of DNCB sensitiza-tion in the buccal pouch prior to or after DMBA tumor induction. At appropriate time intervals the hamsters were sacrificed and each cheek pouch was examined histologically for the development of DMBA-induced tumors and for the presence of lymphoid cells infil-trating the tumor site. The results show that DNCB immunotherapy or immunoprophylaxis prior to or following DMBA tumor inductio