Effects of antibodies to choriogonadotropin in malignant growth. II. Solid transplantable rat tumors.

We have studied the effects of preimmunization with a conjugate of beta-subunit of choriogonadotropin and tetanus toxoid (CG beta-tt) on the growth of the implanted R 3230 AC mammary adenocarcinoma (in Fischer 344 rats) and the implanted 5123 1-1 hepatoma (in Buffalo rats) after 20 days, in order to determine if the in vivo production of antibodies against CG could modify the relationship between host and malignant growth. The results obtained demonstrated that active immunization against CG retarded significantly (P less than 0.01) the growth of the two transplantable tumors. Anti-CG antibodies were also determined and constantly found in the sera of all the preimmunized rats of both strains while no antibodies to CG were found in the control animals.