Salvage gastrectomy after intravenous and intraperitoneal paclitaxel (PTX) administration with oral S-1 for peritoneal dissemination of advanced gastric cancer with malignant ascites.

Background: Peritoneal metastasis of gastric cancer has extremely poor clinical outcomes. Recently, we developed a combination chemotherapy that used intraperitoneal (IP) paclitaxel (PTX) and produced excellent antitumor effects against peritoneal lesions. However, no information is available about the benefit of gastrectomy in cases with malignant ascites.

Methods: A total of 64 patients with severe peritoneal metastasis and ascites received IP PTX at 20 mg/m(2) via implanted subcutaneous peritoneal access ports as well as intravenous (IV) PTX at 50 mg/m(2) on days 1 and 8. S-1 was administered at 80 mg/m(2) day for 14 consecutive days, followed by 7 days of rest. In all patients, investigative laparoscopy was performed around the combination chemotherapy, and gastrectomy was performed on patients who showed apparent shrinkage of their peritoneal nodules as well as negative peritoneal cytology at the second laparoscopy.

Results: Gastrectomy was performed in 34 patients. The median course of chemotherapy before surgery was 5 courses (range 2-16). R0 operation was achieved in 22 patients (65%), and grade 2 and 3 histological responses were obtained in 7 (21%) and 1 (3%) patient(s), respectively. The median survival time and 1-year overall survival of the gastrectomized patients were 26.4 months and 82%, and those of the 30 patients who did not receive gastrectomy were 12.1 months and 26%, respectively. Morbidity was minimal, and there was no mortality.

Conclusions: Salvage gastrectomy after chemotherapy of S-1 with IV and IP PTX is promising, even for patients with highly advanced gastric cancer and severe peritoneal metastasis and malignant ascites.