[Effect of cisplatin (CDDP) against peritonitis carcinomatosa in nude mice inoculated intraperitoneally with human gastric cancer].

Development of effective chemotherapy for patients with peritonitis carcinomatosa is considered to be very important in cancer management. In this study, intraperitoneal injection (ip) of cisdichlorodiammineplatinum (II) (CDDP, cisplatin) together with subcutaneous injection (sc) of sodium thiosulfate (STS), abbreviated as 2-channel chemotherapy, were discussed with regard to its safety and efficacy on peritonitis carcinomatosa using nude mice inoculated intraperitoneally with SCK-8 tumor cells derived from human gastric cancer. A single ip lethal dose (16 mg/kg) of CDDP reproducibly caused weight loss in nude mice and killed 100% of the nude mice by day 5 after injection. However, sc of STS (1,200 mg/kg) protected nude mice against a lethal dose of CDDP, and reduced CDDP-induced weight loss. Two-channel chemotherapy (CDDP 16 mg/kg ip + STS 1200 mg/kg sc) using nude mice with advanced peritonitis carcinomatosa produced a 45% increase of life span with a survival of 74.6 +/- 6.2 days (n = 8), compared with control nude mice with peritonitis carcinomatosa surviving 51.5 +/- 13.3 days (n = 11). Therefore, it is conceivable that 2-channel chemotherapy can be applied to the management of cancer patients with peritonitis carcinomatosa.