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Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2016; 22(28): 6362-6372
Published online Jul 28, 2016. doi: 10.3748/wjg.v22.i28.6362
Immunotherapy in human colorectal cancer: Challenges and prospective
Xuan Sun, Jian Suo, Jun Yan
Xuan Sun, Jian Suo, Department of Gastrointestinal Surgery, The First Hospital, Jilin University, Changchun 130021, Jilin Province, China
Jun Yan, James Graham Brown Cancer Center, Department of Medicine, University of Louisville School of Medicine, Louisville, KY 40202, United States
Author contributions: Sun X, Suo J and Yan J analyzed literature and wrote the manuscript.
Conflict-of-interest statement: The authors have no conflict of interests to report.
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: Jun Yan, MD, PhD, James Graham Brown Cancer Center, Department of Medicine, Clinical & Translational Research Building, Rm 319, University of Louisville School of Medicine, 505 South Hancock Street, Louisville, KY 40202, United States. jun.yan@louisville.edu
Telephone: +1-502-8523628 Fax: +1-502-8522123
Received: March 25, 2016
Peer-review started: March 25, 2016
First decision: May 12, 2016
Revised: June 2, 2016
Accepted: June 15, 2016
Article in press: June 15, 2016
Published online: July 28, 2016
Abstract

Human colorectal cancer (CRC) is the third most commonly diagnosed malignancies and the prognosis for patients with recurrent or metastatic disease is extremely poor. Although new chemotherapeutic regimen improves survival rates, therapy with better efficacy and less adverse effects is drastically needed. Immunotherapy has been investigated in human CRC for decades with limited success. However, recent developments of immunotherapy, particularly immune checkpoint inhibitor therapy, have achieved promising clinical benefits in many types of cancer and revived the hope for utilizing such therapy in human CRC. In this review, we will discuss important immunological landscape within the CRC microenvironment and introduce immunoscore system to better describe immunophenotyping in CRC. We will also discuss different immunotherapeutic approaches currently utilized in different phases of clinical trials. Some of those completed or ongoing trials are summarized. Finally, we provide a brief prospective on the future human CRC immunotherapy.

Keywords: Immunotherapy, Human colorectal cancer, Adoptive cell therapy, Immune checkpoint inhibitor therapy, Immunosuppression

Core tip: Immunotherapy has recently achieved great clinical objective response in multiple cancer types. However, immunotherapy in human colorectal cancer (CRC) is still in its infancy. Identifying CRC patients who are responding to different forms of immunotherapy is drastically needed. In this review, we will discuss important immunological landscape within the CRC microenvironment and introduce immunoscore system to better describe immunophenotyping in CRC. Knowledge gained from these studies may provide rational design for immunotherapy in human CRC patients.