Improved therapeutic effect of sequential immunotherapy with cyclophosphamide, large doses of OK-432 and recombinant interleukin-2 in breast cancer patients with disseminated metastatic liver tumors

It has been generally agreed that the prognosis of widely spreaded "surgically unresectable" metastatic liver tumor originated from breast cancer is very poor. We reported here the result of clinical efficacy of sequential immunotherapy with intra-tumoral injection of large dose OK-432, after oral administration of cyclophosphamide during 7-10 days, and continuous perfusion of purified human recombinant interleukin-2 (rIL-2) from hepatic artery for the breast cancer patients with unresectable metastatic liver tumors. In all of 3 cases, metastatic liver tumor revealed overwhelming tumor reduction more than 50% of preoperative total tumor burden evaluated by computed tomography. Only 1 day after operation, large doses of OK-432 was injected intratumorally, both activity of Natural Killer (NK) cells and lymphokine activated killer (LAK) cells in peripheral blood lymphocytes were 5-20 folds augmented in all clinical trials. Serum tumor markers, i.e., Carcinoembryonic Antigen (CEA) and CA15-3, were rapidly decreased in all cases, respectively. Our clinical data indicate that intratumoral injection of large dose OK-432 and continuous administration of rIL-2 via hepatic artery, pretreated with cyclophosphamide, were clinically effective immunotherapy for reduction of metastatic liver tumor.