AbstractThe therapeutic effect of OK-432 induced endogenous TNF on tumor bearing mice and cancer patients was investigated.OK-432 (10 KE/mouse) was administered intraperitoneally to Balb/c mice 7 days prior to the transplantation of Meth A cells (1×106/mouse) into the abdominal cavity. And at day 1 of tumor inoculation, 1 KE/mouse of OK-432 was administered intraperitoneally.The significant prolongation of life span was observed in these mice.On the basis of these observation, therapeutic effect of endogenous TNF on cancer patients was clinically evaluated. OK-432 was administered intraperitoneally or intrapleurally to cancer patients with peritonitis carcinomatosa or pleuritis carcinomatosa 4 times (10KE each) every other day and 50KE of OK-432 was readministered with the interval of 7 days.An appreciable activity of TNF was detected in peritoneal fluids or pleural effusion, and the significant decreasing of these fluids was observed. It is therefore concluded that these therapeutic approach may well be taken into account in treatment of cancer.