Copyright ©The Author(s) 2022. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Jan 15, 2022; 14(1): 230-241
Published online Jan 15, 2022. doi: 10.4251/wjgo.v14.i1.230
Early-onset colorectal cancer: Current insights and future directions
Claudia Wing-Kwan Wu, Rashid N Lui
Claudia Wing-Kwan Wu, Rashid N Lui, Division of Gastroenterology and Hepatology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Hong Kong, China
Rashid N Lui, Department of Clinical Oncology, The Chinese University of Hong Kong, Hong Kong, China
Author contributions: Wu CWK and Lui RN contributed equally to this work; all authors have read and approved the final manuscript.
Conflict-of-interest statement: All authors have no conflicts of interest to disclose.
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:
Corresponding author: Rashid N Lui, MBChB, FRCP, Clinical Assistant Professor (Honorary), Division of Gastroenterology and Hepatology, Department of Medicine and Therapeutics, The Chinese University of Hong Kong, Shatin, New Territories, Hong Kong, China.
Received: June 16, 2021
Peer-review started: June 16, 2021
First decision: July 29, 2021
Revised: August 2, 2021
Accepted: November 24, 2021
Article in press: November 24, 2021
Published online: January 15, 2022

Early-onset colorectal cancer (EOCRC) has seen an alarming rise worldwide over the past two decades. The reason for this global trend is poorly understood. EOCRC appears to have its own unique clinical and molecular features when compared with late-onset colorectal cancer. Younger patients appear to have more distal or rectal disease, a more advanced stage of disease at presentation, and more unfavorable histological features. Identifying risk factors for EOCRC is the first step in mitigating the rising burden of this disease. Here we summarize several noteworthy biological factors and environmental exposures that are postulated to be responsible culprits. This can hopefully translate in clinical practice to the development of better risk stratification tool for identifying high-risk individuals for early colorectal cancer screening, and identifying areas needed for further research to curb this rising trend.

Keywords: Early-onset colorectal cancer, Young-onset colorectal cancer, Risk factors, Environmental exposures, Microbiome, Genetics

Core Tip: The incidence of early onset colorectal cancer is on the rise. Herein, we discuss on various risk factors that have been implicated for these recent trends and point to where future research needs to be directed for better utilization of healthcare resources. Early recognition and diagnosis are essential for better outcomes of this preventable cancer.