Conversion Surgery Post-Intraperitoneal Paclitaxel and Systemic Chemotherapy for Gastric Cancer Carcinomatosis Peritonei. Are We Ready?

Peritoneal metastasis is common in gastric cancer. It is difficult to treat and carries a poor prognosis. Intraperitoneal (IP) delivery of chemotherapy can attain a higher drug exposure in the peritoneal cavity but with reduced systemic toxicity. Therefore, we hypothesized that IP paclitaxel with systemic chemotherapy would be clinically beneficial for gastric cancer with peritoneal metastases. Patients with unresectable and/or recurrent gastric adenocarcinoma with peritoneal dissemination and/or positive peritoneal washing cytology were recruited. They underwent eight cycles of IP paclitaxel and systemic XELOX. The primary endpoint was 1-year overall survival rate and secondary endpoints were safety, response rate, and peritoneal cytological response. Patients who subsequently had no distant metastases and two consecutive negative peritoneal cytologies underwent conversion gastrectomy if there was no macroscopic evidence of peritoneal disease at diagnostic laparoscopy. Twenty-two patients were enrolled, receiving at least one cycle of IP paclitaxel at the time of reporting (data cutoff-March 11, 2016). The median number of cycles was 7.5. The median overall survival was 18.8 months, and the 1-year survival rate was 72.2%. One patient died of neutropenic sepsis. Of 19 evaluable patients with measurable disease, 7 (36.8%) achieved PR, 8 (42.1%) achieved SD, and 4 (21.1%) experienced PD. Peritoneal cytology turned negative in 11 of 17 (64.7%) patients. Six patients underwent conversion gastrectomy (4 R0, 2 R1) with a median survival of 21.6 months (range = 8.7-29.9 months). XELOX and IP paclitaxel appears to be an effective regimen in gastric cancer with peritoneal metastases. Conversion gastrectomy may be considered in patients with a favorable response.