Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Mar 7, 2018; 24(9): 1022-1034
Published online Mar 7, 2018. doi: 10.3748/wjg.v24.i9.1022
Prognostic value of lymph nodes count on survival of patients with distal cholangiocarcinomas
Hua-Peng Lin, Sheng-Wei Li, Ye Liu, Shi-Ji Zhou
Hua-Peng Lin, Sheng-Wei Li, Department of Hepatobiliary Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
Ye Liu, Department of Neonatal, Children’s Hospital Chongqing Medical University, Chongqing 400016, China
Shi-Ji Zhou, Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, Chongqing 400010, China
Author contributions: Zhou SJ and Lin HP conducted the analyses and wrote the manuscript; all other authors contributed to the idea of the manuscript and approved the final version.
Supported by the National Natural Science Foundation of China, No. 81301975; and the Chongqing Natural Science Foundation, No. cstc2016jcyjA016.
Institutional review board statement: This article does not contain any studies with human participants or animals performed by any of the authors.
Informed consent statement: As this study is based on a publicly available database without identifying patient information, informed consent was not needed.
Conflict-of-interest statement: All authors declare no conflicts-of-interest related to this article.
Data sharing statement: No additional data are available.
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: Shi-Ji Zhou, MD, PhD, Doctor, Surgeon, Surgical Oncologist, Department of Gastrointestinal Surgery, The Second Affiliated Hospital of Chongqing Medical University, 74 Linjiang Road, Yuzhong District, Chongqing 400010, China. zhoushiji@hospital.cqmu.edu.cn
Telephone: +86-23-63693626 Fax: +86-23-63693533
Received: December 23, 2017
Peer-review started: December 23, 2017
First decision: January 17, 2018
Revised: January 30, 2018
Accepted: February 8, 2018
Article in press: February 8, 2018
Published online: March 7, 2018
Processing time: 71 Days and 19 Hours
Abstract
AIM

To evaluate the prognostic value of the number of retrieved lymph nodes (LNs) and other prognostic factors for patients with distal cholangiocarcinomas, and to determine the optimal retrieved LNs cut-off number.

METHODS

The Surveillance, Epidemiology and End Results database was used to screen for patients with distal cholangiocarcinoma. Patients with different numbers of retrieved LNs were divided into three groups by the X-tile program. X-tile from Yale University is a useful tool for outcome-based cut-point optimization. The Kaplan-Meier method and Cox regression analysis were utilized for survival analysis.

RESULTS

A total of 449 patients with distal cholangiocarcinoma met the inclusion criteria. The Kaplan-Meier survival analysis for all patients and for N1 patients revealed no significant differences among patients with different retrieved LN counts in terms of overall and cancer-specific survival. In patients with node-negative distal cholangiocarcinoma, patients with four to nine retrieved LNs had a significantly better overall (P = 0.026) and cancer-specific survival (P = 0.039) than others. In the subsequent multivariate analysis, the number of retrieved LNs was evaluated to be independently associated with survival. Additionally, patients with four to nine retrieved LNs had a significantly lower overall mortality risk [hazard ratio (HR) = 0.39; 95% confidence interval (CI): 0.20-0.74] and cancer cause-specific mortality risk (HR = 0.32; 95%CI: 0.15-0.66) than other patients. Additionally, stratified survival analyses showed persistently better overall and cancer-specific survival when retrieving four to nine LNs in patients with any T stage of tumor, a tumor between 20 and 50 mm in diameter, or a poorly differentiated or undifferentiated tumor, and in patients who were ≤ 70-years-old.

CONCLUSION

The number of retrieved LNs was an important independent prognostic factor for patients with node-negative distal cholangiocarcinoma. Additionally, patients with four to nine retrieved LNs had better overall and cancer-specific survival rates than others, but the reason and mechanism were unclear. This conclusion should be validated in future studies.

Keywords: Distal cholangiocarcinomas; Lymph node count; Survival analysis; SEER

Core tip: The prognostic value of retrieved lymph node (LN) counts is still under debate for patients with distal cholangiocarcinomas. The aim of the present study was to evaluate the prognostic value of the number of retrieved lymph nodes and other prognostic factors for patients with distal cholangiocarcinomas and to determine the optimal retrieved LNs cut-off number. A total of 449 patients with distal cholangiocarcinoma were included in this study. The univariate and multivariate analyses revealed that the number of retrieved LNs was independently associated with survival. And, patients with four to nine retrieved LNs had a better overall and cancer-specific survival rate than others.