Castration effects on tumor specific immunity.

Using two immunogenic methylcholanthrene-induced fibrosarcomas in CD2F1 male mice, initial observations suggested that the rate of tumor growth might be enhanced by castration. For confirmation, tumor transplantation experiments using more than 500 mice were carried out in order to compare tumor specific transplantation immunity in castrate and in control male mice. Inbred mice bearing a 3-methylcholanthrene-induced fibrosarcoma transplant underwent surgical excision of the tumor; and specific resistance to subsequent challenges using varying doses of that tumor cell line were compared in castrate and in noncastrate groups of mice. Although castration influenced the rate of tumor growth, castration had no apparent effect on tumor specific immunoresistance. Mechanisms of host-tumor immunorelationships are discussed.