[Antitumor activities of oily suspended zinostatin stimalamer (YM 881) against VX2 carcinoma implanted in the liver of rabbits--comparison with another anticancer agent].

We previously found that a lipid contrast medium, lipiodol, remained selectively in hepatic tumors after injection via the hepatic artery. YM 881 (MW 15,000) is a conjugate protein preparation of two copolymer of styren-maleic acid (MW 1,500) and neocarzinostatin (MW 11,753). Antitumor activity of YM 881 suspended in lipiodol and aqueous solution of 4'-epi-adriamycin injected arterially against VX2 carcinoma implanted in the liver of rabbits was examined. Based on the growth and histological findings of the tumor, remarkable antitumor activity was observed in the rabbits given YM 881 suspended in lipiodol of a dose of 0.2 mg/body. Compared with 0.05 mg/body, 0.1 mg/body, 0.2 mg/body of YM 881 in lipiodol, antitumor activity was proved to be dose dependent. Antitumor activity of aqueous solution of 4'-epi-adriamycin was moderate and the side effects were observed severely in the group that received aqueous solution of 4'-epi-adriamycin of 6 mg/body. These results suggest that targeting of the anticancer agent carried with lipiodol to tumor is important for the treatment of solid malignant tumors.