[Intraperitoneal infusion therapy of MTX and 5-FU for advanced gastric cancer and its peritoneal metastasis]

We administered methotrexate (MTX) and 5-fluorouracil (5-FU) into the peritoneal cavity as chemotherapy after operation for advanced gastric cancer from a port implanted subcutaneously during the operation, every or every other week. It has been said that MTX tends to be kept in the peritoneal cavity, so the kinetics of MTX is important when it was administered there in. We investigated the concentrations of MTX in the peritoneal cavity and serum with infusion into the peritoneal cavity (IP), and compared it with intraarterial (IA) and intravenous (IV) administration. The results were the lower serum concentration of MTX in IP than in both IA and IV at 1-2 hours after infusion, but thereafter it was the same level in each group. The intraperitoneal concentration of MTX was lower than the detectable level at 24-48 hours after infusion. On the other hand, we investigated the side effects of this therapy, and only one of 20 cases given therapy many times had nausea and vomiting. So the intraperitoneal infusion therapy of MTX and 5-FU seemed to be safe.