Phase II study of weekly intravenous and intraperitoneal paclitaxel combined with S-1 for advanced gastric cancer with peritoneal metastasis

BackgroundA phase II study to evaluate the efficacy and tolerability of weekly i.v. and i.p. paclitaxel (PTX) combined with S-1 was carried out in gastric cancer patients with peritoneal metastasis.Patients and methodsGastric cancer patients with peritoneal dissemination and/or cancer cells on peritoneal cytology were enrolled. PTX was administered i.v. at 50 mg/m² and i.p. at 20 mg/m² on days 1 and 8. S-1 was administered at 80 mg/m²/day for 14 consecutive days, followed by 7 days rest. The primary end point was the 1-year overall survival (OS) rate. Secondary end points were the response rate, efficacy against malignant ascites and safety.ResultsForty patients were enrolled, including 21 with primary tumors with peritoneal dissemination, 13 with peritoneal recurrence and six with positive peritoneal cytology only. The median number of courses was 7 (range 1–23). The 1-year OS rate was 78% (95% confidence interval 65% to 90%). The overall response rate was 56% in 18 patients with target lesions. Malignant ascites disappeared or decreased in 13 of 21 (62%) patients. The frequent grade 3/4 toxic effects included neutropenia (38%), leukopenia (18%) and anemia (10%).ConclusionCombination chemotherapy of i.v. and i.p. PTX with S-1 is well tolerated and active in gastric cancer patients with peritoneal metastasis.