Retrospective Study
Copyright ©The Author(s) 2019. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jan 26, 2019; 7(2): 145-155
Published online Jan 26, 2019. doi: 10.12998/wjcc.v7.i2.145
New metastatic lymph node classification for early gastric cancer should differ from those for advanced gastric adenocarcinoma: Results based on the SEER database
Jian-Xian Lin, Jun-Peng Lin, Ping Li, Jian-Wei Xie, Jia-Bin Wang, Jun Lu, Qi-Yue Chen, Long-Long Cao, Mi Lin, Ru-Hong Tu, Chao-Hui Zheng, Chang-Ming Huang
Jian-Xian Lin, Jun-Peng Lin, Ping Li, Jian-Wei Xie, Jia-Bin Wang, Jun Lu, Qi-Yue Chen, Long-Long Cao, Mi Lin, Ru-Hong Tu, Chao-Hui Zheng, Chang-Ming Huang, Department of Gastric Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, Fujian Province, China
Jian-Xian Lin, Jun-Peng Lin, Ping Li, Jian-Wei Xie, Jia-Bin Wang, Jun Lu, Qi-Yue Chen, Long-Long Cao, Mi Lin, Ru-Hong Tu, Chao-Hui Zheng, Chang-Ming Huang, Department of General Surgery, Fujian Medical University Union Hospital, Fuzhou 350001, Fujian Province, China
Jian-Xian Lin, Ping Li, Jia-bin Wang, Chang-Ming Huang, Key Laboratory of Ministry of Education of Gastrointestinal Cancer, Fujian Medical University, Fuzhou 350108, Fujian Province, China
Author contributions: Lin JX, Lin JP, and Huang CM conceived of the study, analyzed the data, and drafted the manuscript; Zheng CH, Li P, Xie JW, and Wang JB helped revise the manuscript critically for important intellectual content; Lu J, Chen QY, Cao LL, Lin M, and Tu RH helped collect the data and design the study; all authors read and approved the final manuscript.
Supported by Scientific and Technological Innovation Joint Capital Projects of Fujian Province, China, No. 2016Y9031; and Construction Project of Fujian Province Minimally Invasive Medical Center, No. [2017]171.
Institutional review board statement: This study was reviewed and approved by the Ethics Committee of the Fujian Medical University Union Hospital (No. 2018KY039).
Informed consent statement: Participants were not required to give informed consent to this retrospective study since the analysis of baseline characteristics used anonymized clinical data.
Conflict-of-interest statement: There is no conflict of interest associated with publication of this manuscript.
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/
Corresponding author: Chang-Ming Huang, MD, Doctor, Professor, Department of Gastric Surgery, Fujian Medical University Union Hospital, No. 29, Xinquan Road, Fuzhou 350001, Fujian Province, China. hcmlr2002@163.com
Telephone: +86-591-83363366 Fax: +86-591-83363366
Received: August 14, 2018
Peer-review started: August 14, 2018
First decision: October 5, 2018
Revised: November 13, 2018
Accepted: November 23, 2018
Article in press: November 24, 2018
Published online: January 26, 2019
Abstract
AIM

To establish an appropriate N classification system for early gastric cancer (EGC).

METHODS

Data from 10714 patients who underwent radical gastrectomy between 1988 and 2011 were retrieved from the National Cancer Institute’s Surveillance, Epidemiology, and End Result database. The overall survival (OS) based on the eighth edition and new tumor lymph node metastasis (TNM) staging systems were compared, and the analysis was repeated in an external validation set from the Fujian Medical University Union Hospital database.

RESULTS

There were no significant differences in OS between N1 and N2 cancers or between N3a and N3b cancers in cases of EGC. The X-tile program identified that the new staging system for EGC consisted of T1N0, T1N1’ [1-6 metastatic lymph nodes (LNs)], and T1N2’ ( ≥ 7 metastatic LNs). Compared with the eighth edition of the TNM staging system, the OS of patients in T1N1’ stage was similar to that of patients with stage IIA disease, whereas the OS of patients in T1N2’ stage was similar to that of patients with stage IIB disease. The new TNM staging system exhibited a slightly lower Akaike Information Criterion value and higher χ2 and c-statistic compared with the eighth edition of the TNM classification system. Similar results were found in the external validation dataset from the external validation set.

CONCLUSION

We have developed an optional new TNM staging system with a better predictive ability that can be used to accurately predict the 5-year OS of patients with EGC.

Keywords: Early gastric cancer, Gastrectomy, Tumor lymph node metastasis classification, N classification, Lymph node, Prognosis

Core tip: The overall survival (OS) was not significantly different between N1 and N2 cancers or between N3a and N3b cancers in cases of early gastric cancer (EGC). We identified a new metastatic lymph node classification for EGC which consisted of T1N1’ (1-6 metastatic LNs) and T1N2’ ( ≥ 7 metastatic LNs). The OS of patients in T1N1’ stage was similar to that of the 8th edition American Joint Committee on Cancer stage IIA disease, while the OS of patients in T1N2’ stage was not significantly different from that of patients with stage IIB disease. The new TNM staging system has a better predictive ability of OS for EGC.