[Experimental studies on continuous hyperthermic peritoneal perfusion in the treatment for peritoneal metastases of cancer].

As a preliminary study to apply thermotherapy or thermochemotherapy to the treatment of peritoneal dissemination of gastric cancer, a continuous hyperthermic peritoneal perfusion (CHPP) was carried out for the experimental peritoneal dissemination of Donryu rats inoculated with AH100B ascitic hepatoma cells (AH100B cells). Firstly, the cytotoxicity of heat on AH100B cells was studied. No cytotoxicity was observed at 37 degrees C, but mild cytotoxicity was noted at 41.5 degrees C, and marked rise in cytotoxicity was seen at 42.5 degrees C. These cytotoxicity increased with addition to Mitomycin C and prolongation of the heating time. Next, on the 1st, 5th and 10th day after inoculation of AH100B cells, the Donryu rats were treated as follows: Group 1; CHPP (37 degrees C for 1 hr), Group 2; CHPP (41.5 degrees C for 1 hr), Group 3; (42.5 degrees C for 1 hr), Group 4; CHPP (41.5 degrees C for 1 hr)+MMC 1 mg/kg (intraperitoneal administration immediately after completion of CHPP). Group 5; MMC 1 mg/kg (intraperitoneal administration). Death within 48 hours after perfusion occurred in one rat of the 41.5 degrees C perfusion group and 14 rats of the 42.5 degrees C perfusion group. Comparison of the survival time on these groups showed the most remarkable life-prolonging effect in CHPP (41.5 degrees C)+MMC group. On the basis of the results of this study, the CHPP method combined with anti-cancer chemotherapy is considered to be an useful treatment for peritoneal dissemination of cancer.