Antitumor activity of killed Corynebacterium parvum suspensions in a murine mammary adenocarcinoma CaD2) system.

We studied the antitumor activity of killed Corynebacterium parvum on the CaD2 mammary adenocarcinoma in DBA/2 mice. Intratumor treatment had little or no effect on subcutaneous tumor growth. Admixture of tumor cells with C. parvum before inoculation completely suppressed tumor growth. No tumor transplantation immunity was detected in mice inoculated with admixtures of C. parvum and tumor cells, but tumors were enhanced under certain circumstances. Growth of a tumor inoculated sc or iv was consistently retarded after iv or ip C. Parvum therapy, but tumors rarely regressed. Tumor transplantation immunity was detected in mice treated iv with C. parvum before surgical excision of established tumors. Certain adverse effects of iv or ip administration of C. parvum were also discussed.