Intravenous and Intraperitoneal Paclitaxel Combined with S-1 for Advanced Gastric Cancer with Peritoneal Metastasis

Abstract

Intravenous and intraperitoneal paclitaxel combined with S-1 was found to be a promising treatment in a phase II trial for advanced gastric cancer with peritoneal metastasis. This regimen cannot be provided in general practice because intraperitoneal administration of paclitaxel has not been approved in Japan. Five patients were allowed to be given this treatment upon approval by the institutional review board at our own expense in order to participate in a forthcoming clinical trial to further explore this regimen under the auspices of the advanced medical evaluation system organized by the Ministry of Health, Labour and Welfare. This 3-week regimen consists of 2 weeks of oral S-1 (80 mg/m²) and intravenous (50 mg/m²) and intraperitoneal (20 mg/m²) paclitaxel administration on day 1 and day 8. Median duration of treatment was 13 months. Four of the 5 patients enrolled achieved progression-free survivals of more than one year. Moreover, 2 of 3 primary gastric cancer patients underwent conversion surgery after 1 year of treatment without obvious peritoneal metastasis. Although grade IV neutropenia was observed in two recurrent cases, dose reduction enabled continuation of the treatment. In conclusion, intravenous and intraperitoneal paclitaxel combined with S-1 seems to be effective and feasible.