Synergistic antitumor effects of carboplatin and interferons on hepatic metastases of colon carcinoma 26 and M5076 reticulum cell sarcoma.

The effects of combination therapy including various antitumor agents and interferon on mice bearing hepatic metastases of colon carcinoma 26 were determined. Combined treatment with interferon-alpha A/D and carboplatin (CBDCA) was associated with a considerably more pronounced antitumor effect than was treatment with either drug alone. Murine interferon-beta and -gamma each also potentiated the antitumor activity of CBDCA. Combination therapy with interferon-alpha A/D and CBDCA also resulted in marked inhibition of hepatic metastasis of M5076 reticulum cell sarcoma. However, interferon-beta did not potentiate the antitumor activity of CBDCA against either subcutaneously implanted colon carcinoma 26 or pulmonary metastases of this tumor. Thus, in our model the combined administration of interferon and CBDCA was associated with a synergistic antitumor effect on hepatic metastases alone.