Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jun 7, 2015; 21(21): 6675-6683
Published online Jun 7, 2015. doi: 10.3748/wjg.v21.i21.6675
Platelet to lymphocyte ratio as a novel prognostic tool for gallbladder carcinoma
Qing Pang, Ling-Qiang Zhang, Rui-Tao Wang, Jian-Bin Bi, Jing-Yao Zhang, Kai Qu, Su-Shun Liu, Si-Dong Song, Xin-Sen Xu, Zhi-Xin Wang, Chang Liu
Qing Pang, Ling-Qiang Zhang, Rui-Tao Wang, Jian-Bin Bi, Jing-Yao Zhang, Kai Qu, Su-Shun Liu, Si-Dong Song, Xin-Sen Xu, Zhi-Xin Wang, Chang Liu, Department of Hepatobiliary Surgery, the First Affiliated Hospital of Medical College, Xi’an Jiaotong University, Xi'an 710061, Shaanxi Province, China
Author contributions: Pang Q, Zhang LQ and Wang RT contributed equally to this work; Pang Q and Liu C designed the research; Zhang LQ, Wang RT and Bi JB collected the data; Zhang LQ, Zhang JY and Liu SS organized the data; Qu K, Song SD and Xu XS performed the follow-ups; Zhang JY and Xu XS analyzed the data; Pang Q and Zhang LQ wrote the paper; and Qu K, Liu SS and Wang ZX revised the paper.
Supported by Hospital Foundation of the First Affiliated Hospital of Xi’an Jiaotong University College of Medicine (Xi’an, China), No. 2013YK36; National Natural Science Foundation of China, No. 81272644 and No. 81072051 (to Liu C).
Ethics approval: The study was reviewed and approved by the First Affiliated Hospital of Xi’an Jiaotong University College of Medicine Institutional Review Board.
Informed consent: Informed written consent was provided by each participant or the participant’s legal guardian prior to enrollment in the study.
Conflict-of-interest: No author had any conflict of interest related to the manuscript.
Data sharing: The technical appendix, statistical code, and dataset are available from the corresponding author at the following email address: liuchangdoctor@163.com. The participants gave informed consent for data sharing. 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: Chang Liu, MD, PhD, Professor, Department of Hepatobiliary Surgery, the First Affiliated Hospital of Medical College, Xi’an Jiaotong University, No. 277 West Yan-ta Road, Xi’an 710061, Shaanxi Province, China. liuchangdoctor@163.com
Telephone: +86-29-82653900 Fax: +86-29-82653905
Received: December 8, 2014
Peer-review started: December 9, 2014
First decision: December 26, 2014
Revised: January 9, 2015
Accepted: February 11, 2015
Article in press: February 11, 2015
Published online: June 7, 2015
Processing time: 184 Days and 23.1 Hours
Abstract

AIM: To preliminarily investigate the prognostic significance of the platelet to lymphocyte ratio (PLR) in patients with gallbladder carcinoma (GBC).

METHODS: Clinical data of 316 surgical GBC patients were analyzed retrospectively, and preoperative serum platelet and lymphocyte counts were used to calculate the PLR. The optimal cut-off value of the PLR for detecting death was determined by the receiver operating characteristic (ROC) curve. The primary outcome was overall survival, which was estimated by the Kaplan-Meier method. The log-rank test was used to compare the differences in survival. Then, we conducted multivariate Cox analysis to assess the independent effect of the PLR on the survival of GBC patients.

RESULTS: For the PLR, the area under the ROC curve was 0.620 (95%CI: 0.542-0.698, P = 0.040) in detecting death. The cut-off value for the PLR was determined to be 117.7, with 73.6% sensitivity and 53.2% specificity. The PLR was found to be significantly positively correlated with CA125 serum level, tumor-node-metastasis (TNM) stage, and tumor differentiation. Univariate analysis identified carcinoembryonic antigen (CEA), CA125 and CA199 levels, PLR, TNM stage, and the degree of differentiation as significant prognostic factors for GBC when they were expressed as binary data. Multivariate analysis showed that CA125 > 35 U/mL, CA199 > 39 U/mL, PLR ≥ 117.7, and TNM stage IV were independently associated with poor survival in GBC. When expressed as a continuous variable, the PLR was still an independent predictor for survival, with a hazard ratio of 1.018 (95%CI: 1.001-1.037 per 10-unit increase, P = 0.043).

CONCLUSION: The PLR could be used as a simple, inexpensive, and valuable tool for predicting the prognosis of GBC patients.

Keywords: Platelets; Lymphocyte; Gallbladder carcinoma; Prognosis; Survival

Core tip: The platelet to lymphocyte ratio (PLR) has been identified as a useful prognostic tool for various types of cancer; however, its prognostic value in gallbladder carcinoma (GBC) has never been investigated. We recruited 316 patients at our institute to determine the significance of the PLR in GBC. It was found to be significantly correlated with the serum level of CA125, tumor-node-metastasis stage, and tumor differentiation. Our results showed that a PLR ≥ 117.7 was independently associated with poor survival in GBC. We emphasize that this ratio could be used as a simple, inexpensive, and valuable tool for predicting the prognosis of GBC.