Extensive intraoperative peritoneal lavage as a standard prophylactic strategy for peritoneal recurrence in patients with gastric carcinoma.

This prospective randomized multicenter study aims to evaluate the efficacy of extensive intraoperative peritoneal lavage followed by intraperitoneal chemotherapy (EIPL-IPC) on the overall 5-year survival of advanced gastric cancer patients with intraperitoneal free cancer cells without overt peritoneal metastasis (CY+/P-). The study also aims to determine the merit and reliability of EIPL-IPC therapy as a prophylactic strategy for peritoneal metastasis. Although the prognosis of advanced gastric cancer patients with CY+/P- is extremely poor, a suitable standard regimen for treating such patients has not yet been established. A total of 88 patients with CY+/P- from 1522 patients with advanced gastric cancer at multicenters were enrolled in this study and were randomly allocated to 3 groups: surgery alone group, surgery plus intraperitoneal chemotherapy (IPC) group, and surgery plus EIPL and IPC (EIPL-IPC) group. Prognostic significance of EIPL-IPC therapy was evaluated by Kaplan-Meier curves, and its value as an independent prognostic factor was assessed by univariate and multivariate analyses. The overall 5-year survival rate of the patients with EIPL-IPC was 43.8%, and this data were significantly better than that of the IPC group (4.6%, P < 0.0001) and the surgery alone group (0%, P < 0.0001). Among various recurrent patterns, the EIPL-IPC group had a significantly lower incidence of peritoneal recurrence than both of the other groups (P < 0.0001). Univariate and multivariate analyses revealed that EIPL was the most significant impact factor. The present study clearly revealed that EIPL-IPC therapy significantly improved the 5-year survival span of advanced gastric cancer patients with CY+/P-. Thus, EIPL-IPC therapy is strongly recommended as a standard prophylactic strategy for peritoneal dissemination.