[Effects of UFT on experimental liver metastases and on the immunologic capacity of the hosts].

An experimental model is introduced for the study on liver metastasis using intrasplenically injected EL-4 and Lewis lung tumor (LLT) cells. The inhibitory effects of UFT, FT and 5-FU on the frequencies of metastatic foci in the liver were compared. All drugs showed inhibitory effect on the frequencies of liver metastasis. However, a high dose of UFT suppressed strongly the frequencies of liver metastasis. In order to compare the immunosuppressive activity of UFT with that of FT and 5-FU at the dose to give 50% inhibition of liver metastasis (MED50), we determined the MED50 values of UFT, FT or 5-FU against liver metastasis of EL-4 and LLT cells. FT and 5-FU were suppressed strongly the humoral response against SRBC, the delayed hypersensitivity against picryl chloride and the phagocytic activity. UFT had no inhibitory effect on immune responses.