Outcome Data of Patients with Peritoneal Carcinomatosis from Gastric Origin Treated by a Strategy of Bidirectional Chemotherapy Prior to Cytoreductive Surgery and Hyperthermic Intraperitoneal Chemotherapy in a Single Specialized Center in Japan

Background. Management of peritoneal disseminated gastric cancer (GC) remains a challenging problem. The purpose of our study was to evaluate the outcome of bidirectional induction chemotherapy [bidirectional intraperitoneal and systemic induction chemotherapy (BIPSC)] in patients with peritoneal carcinomatosis (PC) arising from GC who underwent cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). Patients and Methods. Overall, 194 patients with PC arising from GC were treated with BIPSC comprising intraperitoneal docetaxel at a dose of 20 mg/m(2) and cisplatin at a dose of 30 mg/m(2) followed by four cycles of oral S-1 at a dose of 60 mg/m(2). CRS and HIPEC were performed in responders to BIPSC. Results. Of these 194 patients, 152 (78.3 %) underwent CRS and HIPEC between January 2005 and December 2012. Treatment-related mortality was 3.9 %, and major complications occurred in 23.6 % of patients. The median survival rate was 15.8 months, with 1-, 2-, and 5-year survival rates of 66, 32 and 10.7 %, respectively, in the patients treated with combined treatment. Multivariate analysis identified pathologic response to BIPSC (p = 0.001), low tumor burden [peritoneal cancer index (PCI) <= 6] (p = 0.001), and completeness of CRS (CC-0, CC-1) (p = 0.001) as independent predictors for a better prognosis. Conclusion. As a viable option, BIPSC with CRS and HIPEC for patients with PC arising from GC may be performed safely, with acceptable morbidity and mortality, in a specialized unit. Response to BIPSC, optimal CRS and limited peritoneal dissemination seem to be essential to achieve the best outcomes in these patients.