The Efficacy of Cytoreductive Surgery with Systemic Chemotherapy for Gastric Cancer with Peritoneal Dissemination

Background: Primary treatment for gastric cancer with peritoneal dissemination is systemic chemotherapy because the effectiveness of cytoreductive surgery remains unclear. This study aimed to investigate the efficacy of cytoreductive surgery with systemic chemotherapy for advanced gastric cancer with peritoneal dissemination. Methods: From 2007 to 2014, 40 patients with peritoneal disseminated gastric cancer received cytoreductive surgery followed by systemic chemotherapy. Clinicopathological characteristics, survival, and prognostic factors were evaluated. Results: Thirty-three patients (82.5%) received S-1 plus cisplatin as a first-line regimen, whereas 22 patients (55%) received second-line chemotherapy with taxane or irinotecan, and 7 patients (17.5%) received four agents (S-1, CDDP, CPT-11, and taxane). The overall survival time was 12 months, whereas the 3and 5-year survival rates were 23% and 16%, respectively. Multivariate analysis revealed synchronous distant metastasis other than to the peritoneum (HR, 4.27; 95% CI, 1.31-13.89; P=0.016) as an independent prognostic factor for survival, but not systemic chemotherapy with four agents, lymph node metastasis, resectability, lymphatic invasion. Conclusions: Although cytoreductive surgery followed by systemic chemotherapy with S-1, cisplatin, taxane, and irinotecan was not an independent prognostic factor for patients with peritoneal dissemination, the detection of distant metastasis before surgery was correlated with poor prognosis. Therefore, we should be administered the strategy to the patients without the detection of distant metastasis.