Extension of Surgical Indication for Gastric Cancer with Peritoneal Metastasis by Intraperitoneal Chemotherapy

Background The prognosis of gastric cancer with peritoneal metastasis is extremely poor. Neither systemic chemotherapy nor surgery alone prolongs survival of patients significantly. Methods Patients diagnosed with advanced gastric cancer underwent staging laparoscopy and received chemotherapy when peritoneal dissemination and/or cancer cells on peritoneal cytology were confirmed. The chemotherapy regimen consisted of S-1, weekly intravenous and intraperitoneal paclitaxel, which was verified in our phase II trial (Ann Oncol 2009). S-1 was administered at 80 mg/m2/day for 14 consecutive days, followed by 7 days rest. Paclitaxel was administered intravenously at 50 mg/m2 and intraperitoneally at 20 mg/m2 on days 1 and 8. Clinical response of chemotherapy was assessed by computed tomography, gastroendoscopy, peritoneal cytology and second-look laparoscopy. Radical gastrectomy was carried out when macroscopic curative resection was made achievable by chemotherapy. Chemotherapy was restarted after operation as soon as possible. Overall survival, relapse free survival, morbidity and mortality of gastrectomy were evaluated. Results Out of 100 patients with peritoneal metastasis who received chemotherapy, 60 patients underwent gastrectomy after response to chemotherapy, including 54 with macroscopic metastasis and 6 with positive peritoneal cytology only. A median of three courses were administered preoperatively (range 1–16). Total or distal gastrectomy with lymphnode dissection was carried out in 54 or 6 patients, respectively. The median survival time was 34.5 months. The median relapse-free survival was 16.7 months. The first site of relapse was the peritoneum in 24 patients and the other organ site in 17 patients. Postoperative complications included anastomotic leakage and pancreatic fistula in two patients each, which were healed conservatively. There were no treatment-related deaths. Conclusions Gastrectomy combined with S-1, intravenous and intraperitoneal paclitaxel is safe and active for gastric cancer patients with peritoneal metastasis.