Letter to the Editor
Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jun 15, 2022; 14(6): 1213-1215
Published online Jun 15, 2022. doi: 10.4251/wjgo.v14.i6.1213
Insight on BRAFV600E mutated colorectal cancer immune microenvironment
Hassan Mohammed Abushukair, Sara Mu'amar Zaitoun, Anwaar Saeed
Hassan Mohammed Abushukair, Faculty of Medicine, Jordan University of Science and Technology, Irbid 22110, Jordan
Sara Mu'amar Zaitoun, Faculty of Medicine, Yarmouk University, Irbid 21163, Jordan
Anwaar Saeed, Department of Medicine, Division of Medical Oncology, The University of Kansas Cancer Center, Kansas City, KS 66205, United States
Author contributions: Abushukair HM and Zaitoun SM drafted the manuscript and contributed to conceptualization; Saeed A contributed to conceptualization of core concepts and critically revised the draft.
Conflict-of-interest statement: Saeed A reports research grants from AstraZeneca, Bristol Myers Squibb, Merck, Exelixis, KAHR Medical, and Incyte, and advisory board fees from AstraZeneca, Bristol Myers Squibb, Merck, Exelixis, and Pfizer. The other authors report no conflicts of interest.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Anwaar Saeed, MD, Department of Medicine, Division of Medical Oncology, The University of Kansas Cancer Center, 2330 Shawnee Mission Pkwy, Suite 210, Kansas City, KS 66205, United States. asaeed@kumc.edu
Received: January 27, 2022
Peer-review started: January 27, 2022
First decision: April 17, 2022
Revised: May 4, 2022
Accepted: May 21, 2022
Article in press: May 21, 2022
Published online: June 15, 2022

Colorectal cancer (CRC) is the second deadliest malignancy for both sexes. The BRAFV600E mutation, one of the most common driver mutations in CRC, is known for its poor prognosis due to the increased risk of metastasis. The effect of the BRAFV600E mutation on the tumor microenvironment was the topic of the study reported in World Journal of Gastrointestinal Oncology, with special focus on immune status. The authors presented insightful findings that were exclusively based on macrophage polarity and cytokine levels, without investigating other relevant immune elements. A more comprehensive look into the dynamic immune activity of cancer environments will warrant more meaningful practical findings. In this letter, we discuss other significant immune factors and their possible implications on the tumor microenvironment of BRAF-mutated CRC.

Keywords: Colorectal cancer, BRAFV600E, Tumor microenvironment, Microsatellite instability, Macrophages, Immune checkpoint proteins

Core Tip: The immune landscape of the tumor microenvironment is a crucial indicator of the proliferative and invasive activity of the tumor cells and serves as a predictor of response to targeted immunotherapeutic modalities. BRAFV600E is one of the most common driver mutations in colorectal cancer thought to have a unique impact on the tumor immune microenvironment. It is unknown whether this impact is of a suppressive or activating nature. Future studies on larger samples, considering a wider array of immune elements, such as the infiltration of relevant immune cells as well as immune checkpoints’ expression, are needed.