Intraperitoneal chemotherapy for gastric cancer with peritoneal disease: experience from Singapore and Japan

Among advanced gastric cancer cases, peritoneal dissemination is a life-threatening mode of metastasis, and any strategy to control peritoneal metastasis will significantly improve treatment outcomes. Since intraperitoneal administration of anticancer drugs can induce an extremely high concentration of drugs in the peritoneal cavity, intraperitoneal chemotherapy would appear to be a reasonable and promising strategy to control the peritoneal dissemination. However, it has been reported in the past that intraperitoneal administration of mitomycin C or cisplatin resulted in no significant clinical effects against peritoneal metastasis of gastric cancer. In contrast, intraperitoneal paclitaxel is expected to remain inside the peritoneal cavity due to its large molecular weight and fat solubility, leading to a high concentration of the drug in the peritoneal cavity. In fact, promising results in several phase II clinical trials using intraperitoneal paclitaxel have been reported, including a median survival time of 16.2-24.6 months and a 1-year overall survival rate of 69-78 %. Thereafter, a phase III randomized control study (PHOENIX-GC trial) with intraperitoneal paclitaxel plus systemic S-1 and intravenous paclitaxel in comparison to systemic S-1 plus cisplatin was conducted in Japan. Moreover, a phase II clinical trial of combination chemotherapy of intraperitoneal paclitaxel with systemic capecitabine plus oxaliplatin is currently ongoing in Singapore. In this review, based on clinical experience from Singapore and Japan, the clinical significance of intraperitoneal chemotherapy for gastric cancer with peritoneal disease is discussed.