Longer survival and fewer metastases by levamisole and tegafur in 1, 2-dimethylhydrazine-induced murine colonic cancers.

The anticancer effects of levamisole, tegafur and their combination were experimentally compared in rats on the 1, 2-dimethylhydrazine (DMH)-induced colonic cancers. DMH at 20 mg/kg of body weight was injected subcutaneously to Donryu rats once a week for 24 weeks long. Nineteen weeks after the start of DMH administration, early colonic cancers were induced and, 28 weeks after, they developed into advanced cancers with distant metastases. From 19 weeks after the start of DMH injection, subcutaneous administration of levamisole at the dose of 2 mg/kg, oral administration of tegafur at 90 mg/kg and their combination were given to the rats daily for nine weeks. The animals were sacrificed 28 weeks after the start of DMH administration. Tegafur was effective, but levamisole with or without tegafur was not effective against early cancer. From 28 weeks after the start of DMH injection, levamisole, tegafur and their combination were administered to the rats daily for four weeks. All of the rats were necropsied when they died. The survival rate and mean survival days were significantly higher and longer in the levamisole groups than in the control rats (p less than 0.05). The incidence of distant metastases was also significantly lower in the levamisole groups than in the control group.