[Pilot study of neo-adjuvant chemotherapy involving intraperitoneal administration of paclitaxel and oral S-1 for patients with T3 gastric cancer].

The prognosis of patients with T3 gastric cancer is poor, even if a curative resection is performed. Novel combination neo-adjuvant chemotherapy has been introduced for T3 gastric cancer patients. This pilot study involving 5 patients was performed between December 2002 and March 2003. They were diagnosed with gastric cancer with serosal invasion (T3) without P1 and CY1 by staging laparoscopy. We selected a combined chemotherapy with both paclitaxel and S-1. Paclitaxel at 60 mg/m2 was administered intraperitoneally on days 1 and 8, and S-1 at 80 mg/m2 was administered orally for 14 days followed by a 7-day-rest, as one course. After one course of this therapy, surgery was performed. The plasma concentration of paclitaxel was measured in two patients. Toxicites were generally mild, and no serious adverse reactions were observed. The plasma concentration of paclitaxel was about 100 ng/mL in the period of 1-6 hours after the administration. After one course, four patients underwent a total gastrectomy and one distal gastrectomy. The final histological stagings were included one stage IB, one stage II, one stage IIIA, one stage IIIB, and one stage IV. Three patients died at 10, 11, and 16 months after the initial treatment, and two have survived for 64 and 62 months. As the intraperitoneal administration of paclitaxel and oral S-1 was well-tolerated, further studies should be conducted involving T3 gastric cancer patients.