Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Sep 14, 2015; 21(34): 9966-9973
Published online Sep 14, 2015. doi: 10.3748/wjg.v21.i34.9966
Prognostic significance of the lymphocyte-to-monocyte ratio in patients with metastatic colorectal cancer
Masatsune Shibutani, Kiyoshi Maeda, Hisashi Nagahara, Hiroshi Ohtani, Katsunobu Sakurai, Sadaaki Yamazoe, Kenjiro Kimura, Takahiro Toyokawa, Ryosuke Amano, Hiroaki Tanaka, Kazuya Muguruma, Kosei Hirakawa
Masatsune Shibutani, Kiyoshi Maeda, Hisashi Nagahara, Hiroshi Ohtani, Katsunobu Sakurai, Sadaaki Yamazoe, Kenjiro Kimura, Takahiro Toyokawa, Ryosuke Amano, Hiroaki Tanaka, Kazuya Muguruma, Kosei Hirakawa, Department of Surgical Oncology, Osaka City University Graduate School of Medicine, Osaka 5458585, Japan
Author contributions: Shibutani M, Maeda K and Hirakawa K designed the research; Shibutani M and Maeda K performed the research; Shibutani M, Maeda K, Nagahara H, Ohtani H, Sakurai K, Yamazoe S, Kimura K, Toyokawa T, Amano R, Tanaka H and Muguruma K collected and analyzed the data; Shibutani M drafted the article; all authors read and approved the final version to be published.
Institutional review board statement: The study was reviewed and approved by the Osaka City University Institutional Review Board.
Informed consent statement: All study participants, or their legal guardians, provided informed written consent prior to study enrollment.
Conflict-of-interest statement: There are no conflicts of interest to report for any of the authors.
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: Masatsune Shibutani, MD, PhD, Department of Surgical Oncology, Osaka City University Graduate School of Medicine, 1-4-3 Asahi-machi, Abeno-Ku, Osaka City, Osaka Prefecture, Osaka 5458585, Japan. fbxbj429@ybb.ne.jp
Telephone: +81-6-66453838 Fax: +81-6-66466450
Received: February 20, 2015
Peer-review started: February 23, 2015
First decision: March 10, 2015
Revised: April 9, 2015
Accepted: May 7, 2015
Article in press: May 7, 2015
Published online: September 14, 2015
Abstract

AIM: To evaluate the prognostic significance of the lymphocyte to monocyte ratio (LMR) in patients with unresectable metastatic colorectal cancer who received palliative chemotherapy.

METHODS: A total of 104 patients with unresectable metastatic colorectal cancer who underwent palliative chemotherapy were enrolled. The LMR was calculated from blood samples by dividing the absolute lymphocyte count by the absolute monocyte count. Pre-treatment LMR values were measured within one week before the initiation of chemotherapy, while post-treatment LMR values were measured eight weeks after the initiation of chemotherapy.

RESULTS: The median pre-treatment LMR was 4.16 (range: 0.58-14.06). We set 3.38 as the cut-off level based on the receiver operating characteristic curve. Based on the cut-off level of 3.38, 66 patients were classified into the high pre-treatment LMR group and 38 patients were classified into the low pre-treatment LMR group. The low pre-treatment LMR group had a significantly worse overall survival rate (P = 0.0011). Moreover, patients who demonstrated low pre-treatment LMR and normalization after treatment exhibited a better overall survival rate than the patients with low pre-treatment and post-treatment LMR values.

CONCLUSION: The lymphocyte to monocyte ratio is a useful prognostic marker in patients with unresectable metastatic colorectal cancer who receive palliative chemotherapy.

Keywords: Colorectal cancer, Prognosis, Unresectable, Chemotherapy, Lymphocyte to monocyte ratio

Core tip: We retrospectively analyzed 104 patients who had unresectable metastatic colorectal cancer. This study indicated that patients with a low pre-treatment lymphocyte to monocyte ratio (LMR) had a significantly worse overall survival rate. Moreover, patients who demonstrated low pre-treatment LMR and normalization after chemotherapy exhibited a better overall survival rate than patients with low pre-treatment and post-treatment LMR values.