Published online Jul 14, 2018. doi: 10.3748/wjg.v24.i26.2886
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
Processing time: 115 Days and 9.9 Hours
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.