Gastrectomy + Cytoreductive Surgery + HIPEC for Gastric Cancer With Peritoneal Dissemination.

Rationale: For gastric cancer patients with peritoneal carcinomatosis palliative systemic chemotherapy is the standard treatment in the Netherlands. There are no potentially curative treatment options. Peritoneal carcinomatosis, in contrast to lymphatic and haematogenous dissemination, should be regarded as locoregional extension of disease. Administering chemotherapeutic drugs directly into the peritoneal cavity has an advantage over systemic chemotherapy since high concentrations of cytotoxic drugs can be delivered directly into the peritoneal cavity with little systemic toxicity. The combination of intraperitoneally administered chemotherapy with cytoreductive surgery and a radical gastrectomy has shown promising results in gastric cancer patients in Asia. As with other gastric cancer issues, the results obtained in Asian patients cannot be extrapolated directly to Western patients. Objective: The primary aim of this study is to compare the overall survival between gastric cancer patients with limited peritoneal carcinomatosis and/ or tumour positive peritoneal cytology treated with gastrectomy, cytoreductive surgery and HIPEC and those treated with the current standard treatment, i.e. palliative systemic chemotherapy. Study design : This is a multicentre randomised controlled two-armed phase III trial. Patients will be randomised (1:1) between palliative systemic chemotherapy only (standard treatment) and gastrectomy combined with cytoreductive surgery and HIPEC (experimental treatment). Study population: Gastric cancer patients are eligible for inclusion if (1) the primary cT3-cT4 gastric tumour including regional lymph nodes is considered to be resectable, (2) limited peritoneal carcinomatosis (\<7) and/ or tumour positive cytology is confirmed by laparoscopy or laparotomy, and (3) systemic chemotherapy (prior to inclusion) was without disease progression. Main study parameters/endpoints: The study sample size (182 patients) is calculated from the hypothesis that the median overall survival of the patients treated according to protocol in the experimental arm is 18 months, as compared to a median overall survival of 10 months in the standard arm. Statistical analysis will be done according to the intention-to-treat principle.