Fumihiko Matsuzawa

Clinical impacts of mesothelin expression in gastrointestinal carcinomas

Mesothelin, C-ERC/mesothelin is a 40-kDa cell surface glycoprotein that is normally present on normal mesothelial cells lining the pleura, peritoneum, and pericardium. Moreover, mesothelin has been shown to be overexpressed in several human cancers, including virtually all mesothelioma and pancreatic cancer, approximately 70% of ovarian cancer and extra bile duct cancer, and 50% of lung adenocarcinomas and gastric cancer. The full-length human mesothelin gene encodes the primary product, a 71-kDa precursor protein. The 71-kDa mesothelin precursor is cleaved into two products, 40-kDa C-terminal fragment that remains membrane-bound via glycosylphosphatidylinositol anchor, and a 31-kDa N-terminal fragment, megakaryocyte potentiating factor, which is secreted into the blood. The biological functions of mesothelin remain largely unknown. However, results of recent studies have suggested that the mesothelin may play a role of cell proliferation and migration. In pancreatic cancer, mesothelin expression was immunohistochemically observed in all cases, but absent in normal pancreas and in chronic pancreatitis. Furthermore, the expression of mesothelin was correlated with an poorer patient outcome in several human cancers. The limited mesothelin expression in normal tissues and high expression in many cancers makes it an attractive candidate for cancer therapy. The present review discusses the expression and function of mesothelin in cancer cells and the utility of mesothelin as a target of cancer therapy.

Serosal Laceration During Firing of Powered Linear Stapler Is a Predictor of Staple Malformation.

Background. Although several types of staplers have been developed, staple-line leaks have been a great problem in gastrointestinal surgery. Powered linear staplers were recently developed to further reduce the risk of tissue trauma during laparoscopic surgery. The aim of this study was to identify the factors that predict staple malformation and determine the effect of precompression and slow firing on the staple formation of this novel powered stapling method. Methods. Porcine stomachs were divided using an endoscopic powered linear stapler with gold reloads. We divided the specimens into 9 groups according to the precompression time (0/60/180 seconds) and firing time (0/60/180 seconds). The occurrence and length of laceration and the shape of the staples were evaluated. We examined the factors influencing successful stapling and investigated the key factors for staple malformation. Results. Precompression significantly decreased the occurrence and length of serosal laceration. Precompression and slow firing significantly improved the optimal stapling formation rate. Univariate analysis showed that the precompression time (0 seconds), firing time (0 seconds), and presence of serosal laceration were significantly associated with a low optimal formation rate. Multivariate analysis showed that these three factors were associated independently with low optimal formation rate and that the presence of serosal laceration was the only factor that could be detected during the stapling procedure. Conclusions. We have shown that serosal laceration is a predictor of staple malformation and demonstrated the importance of precompression and slow stapling when using the powered stapling method.

Long‑term survival and prognosis associated with conversion surgery in patients with metastatic gastric cancer

In gastric cancer, primary systemic chemotherapy is the standard approach for the management of patients with initially unresectable metastasis, and it occasionally leads to a reduction in the size of the lesion, which facilitates surgical resection. The aim of this study was to examine the prognosis of patients who were able to undergo complete resection following chemotherapy. A total of 10 patients who underwent radical surgery for stage IV primary gastric cancer after chemotherapy between 2009 and 2015 at the Department of Surgery of Hokkaido Social Work Association Obihiro Hospital (Obihiro, Japan) were retrospectively investigated. Three regimens were used (S-1, n=1; S-1 + cisplatin, n=8; and S-1 + docetaxel, n=1). The mean time from chemotherapy to surgery was 210 days. One total gastrectomy + splenectomy + colectomy, one total gastrectomy + splenectomy, four total gastrectomies and three distal gastrectomies were performed. There were two cases of pancreatic fistula formation postoperatively. All the patients survived for >1 year. Of the 10 patients, 5 survived without recurrence. The median survival time was 871.1 days after diagnosis. Therefore, curative resection after chemotherapy is associated with a better prognosis in stage IV gastric cancer patients.

The anti-mesothelin monoclonal antibody amatuximab enhances the anti-tumor effect of gemcitabine against mesothelin-high expressing pancreatic cancer cells in a peritoneal metastasis mouse model

Pancreatic cancer often has a very poor prognosis, even after complete resection. The recurrence of hepatic and peritoneal metastases is an important prognostic factor; therefore, the development of improved adjuvant therapy is urgently required. Mesothelin is a cell surface glycoprotein whose expression is restricted to a variety of cancer types, including pancreatic cancer. This expression pattern makes mesothelin an attractive target for cancer therapy, and several agents targeting mesothelin are currently in clinical trials. Here, we used the chimerized high-affinity anti-mesothelin monoclonal antibody amatuximab to investigate its effect on peritoneal metastasis. We used the AsPC-1 pancreatic cancer cell line engineered to express Gaussia luciferase (Gluc), (AsPC-1-Gluc) for in vivo experiments. Results showed that while amatuximab was not directly cytotoxic on an AsPC-1-Gluc tumor cells in a peritoneal metastasis model, it prevented the formation of tumor growth. In combination therapy with gemcitabine, amatuximab exhibited synergistic killing. Our results suggest that blockade of mesothelin by amatuximab may be a useful strategy for preventing the peritoneal dissemination of pancreatic cancer under an adjuvant setting.

L-Carnitine supplementation reduces the general fatigue of cancer patients during chemotherapy

L-Carnitine (LC) plays an important role in the metabolism of fatty acids, and LC deficiency is associated with a feeling of weakness or general fatigue. Cancer patients receiving chemotherapy often develop LC deficiency, which is considered to be a factor contributing to general fatigue. The aim of the present study was to evaluate the efficacy of LC supplementation as a treatment for general fatigue in cancer patients during chemotherapy. A total of 11 cancer patients who were suffering from general fatigue during chemotherapy in our hospital between September 2014 and December 2015 were examined (6 cases involved adjuvant chemotherapy and 5 cases involved chemotherapy for unresectable or recurrent disease). The patients were administered 1,500 mg/day of levocarnitine per os, and the change in mean daily fatigue from the baseline to 8 weeks was assessed using the Brief Fatigue Inventory. The change in the plasma levels of albumin and the lymphocyte counts from the baseline to 8 weeks were also assessed. LC supplementation reduced general fatigue in all cases. Moreover, LC supplementation maintained the plasma levels of albumin and lymphocyte counts during chemotherapy, and enabled patients to continue chemotherapy sequentially without dose reduction. Therefore, LC supplementation improved general fatigue in all the examined cancer patients during chemotherapy. This treatment may make improve the tolerability of chemotherapy in cancer patients by reducing general fatigue and improving the nutritional status.

Rare case of idiopathic sclerosing cholangitis, which was difficult to distinguish from cholangiocarcinoma: A case report

It is often difficult to correctly diagnose patients who present with dilation of the bile duct. Cholangiocarcinoma, primary sclerosing cholangitis (PSC) and immunoglobulin (Ig)G4-related sclerosing cholangitis must be considered as potential diagnoses for these cases. The current study presents a 73-year-old female patient who presented with a high fever and abdominal pain. Contrast-enhanced computed tomography and magnetic resonance cholangiopancreatography revealed stenosis and dilation of the intrahepatic bile duct without solid components. It was suspected that the patient had intrahepatic cholangiocarcinoma. A left liver lobectomy, cholecystectomy and distal gastrectomy combined with a D2 lymph node dissection were performed. A pathological examination of the liver revealed increased fibrosis in the stroma, irregular bile duct dilation and clusters of inflamed lymph cells. No carcinoma or IgG4-positive plasma cells were observed and the typical findings of PSC were not detected. Based on these clinical and pathological results, the diagnosis was idiopathic sclerosing cholangitis, which is particularly rare. It is often difficult to preoperatively differentiate between cholangiocarcinoma and benign bile duct stenosis.

Mesothelin-Specific Immune Responses and Targeted Immunotherapy for Mesothelin-Expressing Tumors

Article history: Received 24 September 2017 Accepted 24 September 2017 Available online 25 September 2017 phatic invasion by increasing cell adhesion to lymphatic endothelial cells (Kawamata et al., 2014). Our group investigated mesothelin expression in gastrointestinal cancers using immunohistochemistry (IHC), especially focusing on the localization of mesothelin, i.e., “luminal membrane-positive” and/or “cytoplasm-positive”. Luminal membrane positive mesothelin repre-