[Intraperitoneal Chemotherapy for Peritoneal Metastasis of Gastric Cancer]

Peritoneal metastasis of gastric cancer remains a refractory disease, and the standard treatment strategy is still unclear. Intraperitoneally administered paclitaxel(PTX)remains in the intraperitoneal(IP)cavity for a long time and directly infiltrates peritoneal metastatic nodules, thereby producing antitumor effects. We designed an IP chemotherapy regimen of S-1 combined with weekly intravenous(IV)and IP PTXadministration. In our phase I study, the recommended dose of IP PTXwas determined to be 20mg/m2. In our phase II study for patients with P1(macroscopic peritoneal metastasis-positive)or CY1 (cytology-positive)gastric cancer, the 1-year overall survival(OS)rate was 78%and the median survival time(MST)was 23.6 months. In another phase II study of patients with P1 gastric cancer, the 1-year OS rate was 77%and the MST was 17.1 months. A phase III PHOENIX-GC trial comparing IP chemotherapy to S-1 plus cisplatin has recently been completed. Phase II studies of the IP administration of docetaxel have also shown favorable results. Recently, the results of several clinical studies investigating the effects of S-1 combined with weekly IV and IP PTXadministration for peritoneal metastasis of pancreatic cancer have been published.