Retrospective Cohort Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 14, 2021; 27(46): 8010-8030
Published online Dec 14, 2021. doi: 10.3748/wjg.v27.i46.8010
Life prognosis of sentinel node navigation surgery for early-stage gastric cancer: Outcome of lymphatic basin dissection
Shinichi Kinami, Naohiko Nakamura, Tomoharu Miyashita, Hidekazu Kitakata, Sachio Fushida, Takashi Fujimura, Yasuo Iida, Noriyuki Inaki, Toru Ito, Hiroyuki Takamura
Shinichi Kinami, Naohiko Nakamura, Tomoharu Miyashita, Hiroyuki Takamura, Department of Surgical Oncology, Kanazawa Medical University, Kahoku 920-0293, Ishikawa, Japan
Hidekazu Kitakata, Toru Ito, Department of Gastroenterological Endoscopy, Kanazawa Medical University, Kahoku 920-0293, Ishikawa, Japan
Sachio Fushida, Noriyuki Inaki, Department of Gastrointestinal Surgery, Kanazawa University, Kanazawa 920-8641, Ishikawa, Japan
Takashi Fujimura, Department of Surgery, Toyama City Hospital, Toyama 939-8511, Toyama, Japan
Yasuo Iida, Department of Mathematics, Division of General Education, Kanazawa Medical University, Kahoku 920-0293, Ishikawa, Japan
Author contributions: Kinami S was responsible for the scientific conception of the study and writing of the manuscript; Kinami S, Nakamura N, Miyashita T, Kitakata H, Fushida S, Fujimura T, and Ito T contributed to the surgery and data collection; Iida Y was responsible for the statistical analysis; Takamura H and Inaki N contributed to the drafting, editing, and critical revision of the manuscript; and all authors contributed to the approval of the final version of the manuscript.
Institutional review board statement: This study was approved by the ethics committee of Kanazawa University Hospital and Kanazawa Medical University (Trial Number R093, M288). ICG mapping was approved by the ethics committee of Kanazawa Medical University (Trial Number M404).
Informed consent statement: All patients provided written informed consent for surgery and the use of their data. Regarding data use in the retrospective study, the patients were given the opportunity to opt out of the study at any time.
Conflict-of-interest statement: The authors declare no conflicts of interest related to the publication of this study.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement checklist of items, and the manuscript was prepared and revised according to the STROBE Statement checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Shinichi Kinami, MD, PhD, Professor, Department of Surgical Oncology, Kanazawa Medical University, 1-1 Daigaku, Uchinada-machi, Kahoku 920-0293, Ishikawa, Japan. kinami@kanazawa-med.ac.jp
Received: May 20, 2021
Peer-review started: May 20, 2021
First decision: June 22, 2021
Revised: June 28, 2021
Accepted: November 29, 2021
Article in press: November 29, 2021
Published online: December 14, 2021
ARTICLE HIGHLIGHTS
Research background

If early gastric cancer patients who are negative for lymph node metastasis can be diagnosed intraoperatively, excessive nodal dissection and extensive gastrectomy can be avoided. Currently, the most effective method for diagnosing lymph node metastasis is sentinel node biopsy. Lymphatic basin dissection is a sentinel node biopsy method that is specific for gastric cancer. The dyed lymphatic system was dissected en bloc and sentinel nodes were identified at the back table (ex vivo) using this method. This method not only reduces the difficulty of sentinel node biopsy, but also serves to a certain extent as backup dissection. Even with lymphatic basin dissection, blood flow to the residual stomach can be preserved and function-preserving curative gastrectomy can be performed, such as segmental gastrectomy and local resection.

Research motivation

The oncological safety of function-preserving curative gastrectomy combined with lymphatic basin dissection has not yet been fully investigated.

Research objectives

This study aimed to investigate the life prognosis of patients with early gastric cancer who underwent sentinel node navigation surgery (SNNS) in comparison with standard guideline surgery.

Research methods

Gastric cancer patients were retrospectively collected. The inclusion criteria were as follows: Superficial type (type 0); preoperative diagnosis of 5 cm or less in length; clinical T1-2; and node-negative on X-computed tomography. The patients underwent SNNS. First, sentinel node mapping was performed, followed by lymphatic basin dissection and rapid intraoperative pathology. If the sentinel nodes were diagnosed as metastasic at rapid diagnosis, standard gastrectomy with nodal dissection up to D2 was performed; if the sentinel nodes were diagnosed as node-negative, the extent of gastrectomy was reduced, and function-preserving curative gastrectomy was performed. The life prognosis and cumulative incidence of metachronous multiple gastric cancer (MMGC) were investigated. Patients with the same inclusion criteria and who underwent standard gastrectomy and guideline lymph node dissection with or without sentinel node biopsy were selected as the control group.

Research results

There were 239 patients in the SNNS group and 423 patients in the control group. All patients were diagnosed as node-negative preoperatively, but pathological nodal metastasis was observed in 10.5% of patients in the SNNS group and 10.4% in the control group. The diagnostic ability of sentinel node biopsy in this study was 84% and 98.6% for sensitivity and accuracy, respectively. In the SNNS group, 18.4% of patients underwent standard surgery, 14.2% had modified gastrectomy, and 67.4% had function-preserving curative gastrectomy, in which the extent of resection was further reduced than that recommended by the guidelines. The overall survival (OS) rate in the SNNS group was 96.8% at 5 years and was significantly better than 91.3% in the control group (P = 0.0014). The relapse-free survival (RFS) rate in the SNNS group was 99.6% at 5 years and 98.1% in the control group. After propensity score matching, there were 231 patients in both groups, and the OS in the SNNS group remained significantly better than that in the control group (P = 0.030). The cumulative recurrence rate in the SNNS group was 0.43% in 5 years and 1.30% in the control group, which was not statistically different. There was no difference in the incidence of MMGC between the SNNS group (1.7% at 5-years) and the control group (2.3% at 5-years).

Research conclusions

In both original data sets and propensity score-matched comparisons, the OS rate and RFS rate of patients who underwent gastrectomy guided by sentinel node navigation were not inferior to those of standard gastrectomy. In addition, there was no difference in the cumulative incidence of MMGC between the two groups.

Research perspectives

The oncological safety of sentinel node navigation surgery for early-stage gastric cancer is not inferior to that of the guideline. This study also indicates the possibility of reducing the extent of nodal dissection to only the lymphatic basin for all patients with cT1N0 less than 5 cm in the future.