The development of a novel intraperitoneal tumor-seeding prophylactic

BACKGROUND: Peritoneal tumor dissemination and implantation is a complication of both open and laparoscopic oncologic surgery. This study evaluates the efficacy of paclitaxel-loaded poly(L-lactic acid) microspheres as prophylaxis against intraabdominal tumor seeding. METHODS: 2 X 10(6) 9L glioblastoma cells were introduced into the abdominal cavity of Wistar rats. Fifteen minutes later, the peritoneal cavity was washed with the experimental solutions, and 2 weeks later the presence of tumor implantation was determined. After defining the optimum dose of paclitaxel PLA microspheres in a dose-ranging study, the microsphere formulation was then compared with conventional paclitaxel in four experimental groups (n = 5) as follows: 100 mg of 30% paclitaxel-loaded microspheres; 100 mg PLA microspheres; paclitaxel 4.1 mg; and controls receiving no intraabdominal therapy. RESULTS: Although carcinomatosis developed in all control animals, none in the paclitaxel-loaded microsphere group had biopsy proven cancer. The conventional paclitaxel group (3) showed significant toxicity; only 1 animal survived and had positive histology. CONCLUSIONS: In this animal model of peritoneal carcinomatosis, the paclitaxel-loaded microsphere formulation was more effective than conventional paclitaxel in preventing tumor seeding. (C) 1997 by Excerpta Medica, Inc.