The role of alpha-difluoromethyl ornithine as an adjuvant to immunotherapy in mice bearing transplantable tumors.

alpha-Difluoromethyl ornithine (DFMO), an inhibitor of ornithine decarboxylase (ODC), depletes cellular polyamine levels which is significantly correlated to neoplastic transformation. DFMO was used to modulate the growth rate of Ehrlich ascites carcinoma in mice and attempts were made to use DFMO as an adjuvant to immunotherapy. The therapeutic efficacy was estimated by measurement of polyamine levels of blood and ODC activity. Significant changes were also observed in the survival of the treated groups of animals, the implications of which have been discussed.