Background: Cytoreductive surgery and hyperthermic intraperitoneal chemotherapy are a combined treatment modality considered for selected patients with peritoneal carcinomatosis from colorectal and appendiceal cancer. Mitomycin C is a drug often used in this clinical setting. The surgical and clinical factors that may influence the pharmacokinetics of hyperthermic intraperitoneal chemotherapy should be further elucidated.
Materials and methods: The patients included were 145 who had colorectal or appendiceal carcinomatosis resected using cytoreductive surgery prior to treatment with hyperthermic intraperitoneal chemotherapy with mitomycin C as part of a multidrug regimen. The effect of clinical and surgical factors on drug distribution after single intraperitoneal bolus administration with mitomycin C was determined.
Results: The pharmacokinetics of 145 patients treated with intraperitoneal mitomycin C showed a 27 times greater exposure to peritoneal surfaces when compared to plasma. At 90 min, 29% of the drug remained in the chemotherapy solution, 62% was retained in the body, and 9% was excreted in the urine. The extent of peritonectomy increased the clearance of mitomycin C from the peritoneal space (p = 0.051). A major resection of visceral peritoneal surface and a contracted peritoneal space reduced drug clearance. A contracted peritoneal space significantly reduced (p = 0.0001) drug concentrations in the plasma.
Conclusions: Surgical and clinical factors may require modifications of drug dose or timing of chemotherapy administration. A large visceral resection and a contracted peritoneal space caused a reduced mitomycin C clearance. Total diffusion surface is an important determinant of mitomycin C pharmacokinetics.