Annual Report 2017

Department of Gastric Surgery

Takahiro Kinoshita, Masanori Tokunaga, Akio Kaito, Hideki Sunagawa, Shizuki Sugita, Masahiro Watanabe

Introduction

 The Department of Gastric Surgery consists of three staff surgeons, three senior residents, and five junior resident surgeons. Our managing of tumors includes common gastric adenocarcinoma, adenocarcinoma of the esophagogastric junction (AEG: Siewert type 2/3), and gastric submucosal tumors (GIST, etc.). Annually, 260 to 300 patients are operated on, either by means of open surgery or laparoscopic surgery (Table 1). Laparoscopic gastrectomy with radical node dissection was introduced in 2010, and now our department is one of the leading institutions in Japan. In 2017, about 90% of gastrectomies were performed under laparoscopy (Table 2). The basis of our surgery is radical extirpation of cancer lesions, but at the same time, organ functions and better quality of life (QOL) should be maintained. In addition, we strive to obtain better clinical outcomes for patients with diseases with dismal prognoses (type 4 gastric cancer or with progressive metastasis) by surgery combined with a modern chemotherapy regimen, including molecular-targeting drugs in cooperation with medical oncologists.

Table 1. Number of patients

Table 2. Type of procedures

Our team and what we do

 Usually 14 to 16 patients are hospitalized, and six to nine patients undergo operations per week. A clinical conference of our department is held once a week to decide our treatment strategy. Further, a conference with internal medicine is held every Monday evening with doctors of the Department of Diagnostic Radiology, Gastroenterology and Endoscopy, and Gastrointestinal Oncology, discussing the accurate diagnosis of patients with gastric tumors to decide the optimal treatment method for each patient. Every Tuesday morning, a small conference is held with medical oncologists to discuss border-line cases. In principle, patients with low-risk superficial gastric cancer lesions (cT1a) are treated by endoscopic submucosal dissection (ESD) following the criteria of the guidelines. Some are required to undergo subsequent completion laparoscopic surgery with nodal dissection based on pathological findings of specimens obtained by ESD. Laparoscopic surgery covers distal, proximal, pylorus-preserving, and total gastrectomy. D2 dissection can also be done under laparoscopy, and its applicability for advanced cancer is under investigation. When the tumor infiltrates into adjacent organs, extended operations are chosen in some cases. Recently, due to the progress of modern chemotherapy regimen, down-staging from cStageIV is sometimes seen. For such patients, we selectively perform conversion surgery to achieve favorable outcomes. For AEGs, the transhiatal approach can be safely employed under laparoscopy with a better surgical view.

Research activities

 We aggressively publish our clinical research data in domestic or international congresses. In addition, we participate in multi-institutional clinical trials conducted by the Japan Clinical Oncology Group (JCOG) - Gastric Surgery Study Group or other international and domestic organizations. Patients with gastric cancer are, if eligible for each study, invited to take part in one of the ongoing clinical trials.

Clinical trials

 The list of clinical trials in which we participated in 2017 are listed below.

1) JCOG1301C: A randomized phase II study of systemic chemotherapy with and without trastuzumab followed by surgery in HER2 positive advanced gastric or esophagogastric junction adenocarcinoma with extensive lymph node metastasis (Trastuzumab In Gastric or Esophagogastric junction Adenocarcinoma

2) JCOG1509: Phase III trial to evaluate the efficacy of neoadjuvant chemotherapy with S-1 plus oxaliplatin followed by D2 gastrectomy with adjuvant S-1 in locally advanced gastric cancer (NAGISA trial)

3) A prospective cohort study to evaluate the proper extent of lymph node dissection for esophagogastric junction cancer

4) A Phase III, Randomized, Double-Blind, Clinical Trial of Pembrolizumab (MK-3475) Plus Chemotherapy (XP or FP) Versus Placebo Plus Chemotherapy (XP or FP) as Neoadjuvant/Adjuvant Treatment for Subjects With Gastric and Gastroesophageal Junction (GEJ) Adenocarcinoma (KEYNOTE-585)

5) Extensive Peritoneal Lavage after Curative Gastrectomy for Gastric Cancer: a Randomized Controlled Trial (EXPEL Study)

6) A phase II study of systemic chemotherapy with S-1 and Oxaliplatin followed by gastrectomy with D2 or D2 plus limited para-aortic lymph node dissection in HER2 negative advanced gastric or esophagogastric junction cancer with extensive lymph node metastasis (SOX-D2 study)

7) Venous Thromboembolism (VTE) in Cancer Patients; a Multicenter Prospective Registry

Education

 Resident doctors are trained to be specialized surgical oncologists with sufficient techniques and knowledge. Nowadays, opportunities to perform laparoscopic and open surgery are simultaneously given to them. We also place importance on the education of surgeons of other institutions. In 2017, surgeons from domestic and foreign hospitals (from China, Taiwan, Portugal, Spain, Colombia, Argentina, and Russian Federation) visited our department to learn surgical techniques.

Future prospects

 We will keep striving to obtain better survival outcomes for patients with far advanced diseases; for multidisciplinary therapy (chemotherapy, molecular-target agents or immune checkpoint inhibitors), collaborating with medical oncologists is essential. Additionally, we will continue to develop less-invasive as well as high quality surgical methods (laparoscopic or robotic surgery), to improve patients' QOL and realize complete cures. It is also our obligation to expand our knowledge and experience globally as one of the most main countries in terms of gastric cancer occurrence.