Effect of immunization with an allogeneic tumor on the growth of primary methylcholanthrene-induced sarcomas in rats.

Making use of common antigenicity among allogeneic tumors, the immunotherapy against primary 3-methylcholanthrene(MCA)-induced sarcomas in rats was attempted. At the time when MCA-induced sarcomas reached approximately 1 cm in diameter, allogeneic Usubuchi sarcoma cells were injected 5 times into the subcutaneous tissue of rats. In most cases, inhibitory effect on the growth of the tumor was observed in the early period, but none of 29 cases treated resulted in final regression. Twenty-nine non-treated cases showed uniformly progressive growth from the beginning. This result seems to indicate the possibility of using allogeneic tumor(s) for the immunotherapy against human cancer.