©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
Impact of the number of examined lymph nodes on outcomes in patients with lymph node-negative gallbladder carcinoma
Dong-Xu Fan, Department of Vascular surgery, First Affiliated Hospital of Jiamusi University, Jiamusi 154002, Heilongjiang Province, China
Rong-Wei Xu, Department of Vascular Surgery, Shandong Provincial Qianfoshan Hospital, Shandong University, Jinan 250014, Shandong Province, China
Yong-Cheng Li, Department of Medical Oncology, Xuzhou Central Hospital, The Affiliated Xuzhou Hospital of Medical College of Southeast University, Xuzhou 221009, Jiangsu Province, China
Bing-Qing Zhao, Department of Surgery, Tianjin Second People’s Hospital, Tianjin 300192, China
Ming-Yu Sun, Department of Breast Surgery, Xuzhou Central Hospital, The Affiliated Xuzhou Hospital of Medical College of Southeast University, Xuzhou 221009, Jiangsu Province, China
Author contributions: Fan DX and Sun MY designed the research and critically revised the manuscript for important intellectual content; all authors performed the research, analyzed the data, and wrote the paper.
Conflict-of-interest statement: All authors declare no competing financial interests.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (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/
Correspondence to: Ming-Yu Sun, MD, Doctor, Department of Breast Surgery, Xuzhou Central Hospital, The Affiliated Xuzhou Hospital of Medical College of Southeast University, No.199 South Jiefang Road, Xuzhou 221009, Jiangsu Province, China. email@example.com
Received: March 19, 2018
Peer-review started: March 20, 2018
First decision: April 24, 2018
Revised: May 2, 2018
Accepted: June 2, 2018
Article in press: June 2, 2018
Published online: July 14, 2018
The American Joint Committee on Cancer (AJCC) tumor-node-metastasis staging system for gallbladder carcinoma (GBC) has been updated recently to the 8th edition. The N category is re-defined by the number of metastatic lymph nodes (LNs) instead of the location of the metastatic LNs, as defined in the 7th edition.
The new staging system for GBC has not been validated yet. Thus, we used Surveillance, Epidemiology, and End Result (SEER) database to evaluate its impact on clinical practice.
The primary purpose of this study was to evaluate the impact of the number of examined LNs on the prognosis of N0 GBC. The secondary purpose was to verify the rationality of the guideline recommendation that at least six LNs should be harvested and evaluated.
Patients were collected from the SEER database (2004-2013) and categorized by the number of LNs into six groups: 1 LN, 2 LNs, 3 LNs, 4 LNs, 5 LNs, and ≥ 6 LNs. Survival curves for overall survival were plotted with a Kaplan-Meier analysis. The log-rank test was used for univariate comparisons.
The survival for the 1 LN group was significantly lower than that of the stage I and II disease groups and for the entire cohort. By dichotomizing the number of LNs from one to six, we found that the minimum number of LNs that should be examined was four for stage I, four or five for stage II, and six for stage IIIA disease. Thus, at least six LNs should be examined for the entire cohort, which was exactly consistent with the AJCC criteria.
The examination of higher numbers of LNs is associated with improved survival after resection surgery for N0 GBC. As recommended in the guidelines, at least six LNs should be examined for patients with N0 GBC.
The results validated the new recommendation in the AJCC guidelines, which can be applied widely in clinical practice.