Akinobu Matsuo

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

Objective: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. Summary Background Data: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. Methods: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. Results: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. Conclusions: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.

A New Procedure of Percutaneous Microwave Coagulation Therapy Under Artificial Hydrothorax for Patients with Liver Tumors in the Hepatic Dome

Abstract Percutaneous microwave coagulation therapy (PMCT) has been widely used as an effective minimal invasive therapy for small liver tumors. The occurrence of a sonographic masked space due to the presence of the lung, however, has become a major obstacle to visualizing the whole tumor in the hepatic dome. To facilitate the use of PMCT for liver tumors in the hepatic dome, we developed PMCT in combination with the artificial hydrothorax method (percutaneous transdiaphragmatic MCT: PTD-MCT). Our new approach for PMCT to the hepatic tumors located in Couinauds segments VIII or VII just under the diaphragm resulted in a successful treatment. The separation of the lung from the diaphragm by the infusion of saline into the pleural cavity enabled us not only to visualize the whole tumor in the hepatic dome to accurately target the tumor, but also helped us to avoid injuring the lung. PTD-MCT is therefore strongly recommended for the treatment of liver tumors in the hepatic dome.

A Proposal of a Practical and Optimal Prophylactic Strategy for Peritoneal Recurrence

Peritoneal metastasis, which often arises in patients with advanced gastric cancer, is well known as a miserable and ill-fated disease. Once peritoneal metastasis is formed, it is extremely difficult to defeat. We advocated EIPL (extensive intraoperative peritoneal lavage) as a useful and practical adjuvant surgical technique for those gastric cancer patients who are likely to suffer from peritoneal recurrence. In this paper, we review the effect of EIPL therapy on prevention of peritoneal recurrence on patients with peritoneal free cancer cells without overt peritoneal metastasis (CY+/P−) through the prospective randomized study, and we verified its potential as an optimal and standard prophylactic therapeutic strategy for peritoneal recurrence.

Establishment of the Standard Prophylactic Strategy for Peritoneal Recurrence and Proposal of the Optimal Therapeutic Protocol for Gastric Cancer

Advances in diagnosis and surgical techniques have improved the conditions of patients with gastric cancer. Peritoneal dissemination, however, is still the most frequent cause of death, and the prognosis of patients with peritoneal metastasis of gastric cancer is extremely poor (Balfour, 1973; Hioki et al.,2010; Maruyama, 1987; Makino et al., 2010; M. Yamamoto et al., 2009). In patients with serosal invasion, about half develop peritoneal recurrence and die from the disease within the first 2 years of follow-up, even if curative resection is performed (Abe et al., 1995; Ikeguchi et al., 1994; Kaibara et al., 1987; Moriguchi et al., 1992; Ribero et al., 1998). Furthermore, it has been reported that the survival span of the patients with cytology-positive peritoneal lavage fluid and without the macroscopic peritoneal dissemination (CY+/P-) of gastric cancer was almost the same as that of patients with P+ (Boku, et al., 1990; Shimada et al., 2003), and the 5-year survival rate of patients with CY+/Pis only 2% (Bando et al., 1999). Accordingly, the treatment recommendations for gastric cancer in the event of positive cytology range from palliative chemotherapy to attempts at neo-adjuvant therapies followed by surgical resection. However, the results of published randomized clinical trials of adjuvant perioperative intra-peritoneal chemotherapy have not fully demonstrated any significant improvement in survival as compared with surgery alone, especially in the cases with P+ (Cunliffe & Sugarbaker, 1989; Cheong et al., 2007; Hagiwara et al., 1992; Ikeguchi et al., 2005; Kunisaki et al., 2002; Sauter et al., 1994). Therefore, a reliable and appropriate standard prophylactic regimen for peritoneal recurrence in patients with gastric cancer needs be established. Clinical and pathologic factors that have been found to correlate with the presence of positive cytology are usually at an advanced stage of the disease (Burke et al., 1998; Iitsuka et al., 1979; Koga et al., 1984; Ribeiro et al.,2006; Yawata et al.,1998). The most likely cause is the presence of intra-peritoneal free cancer cells from the serosal surface of the primary cancer and their implantation on the peritoneum. Furthermore, our previous study proved