Leung LJCL, Sharma RS, Cheng B, Akalanka HK, Gopalan V. Obesity and colorectal cancer risk: A systematic review and meta-analysis. World J Clin Oncol 2026; 17(1): 112369 [DOI: 10.5306/wjco.v17.i1.112369]
Corresponding Author of This Article
Lachlan James Chun-Lok Leung, School of Medicine and Dentistry, Griffith University, 20f Parklands Dr, Southport, Gold Coast 4215, Queensland, Australia. leunglachlan@gmail.com
Research Domain of This Article
Gastroenterology & Hepatology
Article-Type of This Article
Meta-Analysis
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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/
Jan 24, 2026 (publication date) through Jan 28, 2026
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Journal Information of This Article
Publication Name
World Journal of Clinical Oncology
ISSN
2218-4333
Publisher of This Article
Baishideng Publishing Group Inc, 7041 Koll Center Parkway, Suite 160, Pleasanton, CA 94566, USA
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Leung LJCL, Sharma RS, Cheng B, Akalanka HK, Gopalan V. Obesity and colorectal cancer risk: A systematic review and meta-analysis. World J Clin Oncol 2026; 17(1): 112369 [DOI: 10.5306/wjco.v17.i1.112369]
Lachlan James Chun-Lok Leung, Rohan Sharad Sharma, Brandon Cheng, Vinod Gopalan, School of Medicine and Dentistry, Griffith University, Gold Coast 4215, Queensland, Australia
HM Kasuni Akalanka, Rural Health Research Institute, Charles Sturt University, Orange 2800, New South Wales, Australia
Co-corresponding authors: Lachlan James Chun-Lok Leung and Vinod Gopalan.
Author contributions: Leung LJCL contributed substantially to the conception and design of the study, acquiring, analysing and interpreting the data, and was a major contributor in the writing of the manuscript; Sharma RS and Cheng B greatly assisted with the analysis and interpretation of the data as well as contributing to the manuscript drafting; Gopalan V assisted with the conception of the study as well as provided critical revisions of the intellectual content of the manuscript draft; Akalanka HMK was also another major contributor of providing critical revisions of the manuscript drafting; Leung LJCL and Gopalan V confirm the authenticity of all the raw data. All authors read and approved the final manuscript. Both authors listed as co-corresponding authors were heavily involved in the concept creation of this paper. They were also involved in the supervision of other authors, data analysis and coordination of writing. As such, it was deemed that both authors should be listed as corresponding authors for this paper due to their contributions to this paper.
Conflict-of-interest statement: The authors declare that there are no conflicts-of-interest.
PRISMA 2009 Checklist statement: The authors have read the PRISMA 2009 Checklist, and the manuscript was prepared and revised according to the PRISMA 2009 Checklist.
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: Lachlan James Chun-Lok Leung, School of Medicine and Dentistry, Griffith University, 20f Parklands Dr, Southport, Gold Coast 4215, Queensland, Australia. leunglachlan@gmail.com
Received: July 25, 2025 Revised: August 13, 2025 Accepted: November 27, 2025 Published online: January 24, 2026 Processing time: 179 Days and 19.7 Hours
Abstract
BACKGROUND
An observed correlation between increased colorectal cancer (CRC) incidence in patients with obesity [body mass index (BMI) ≥ 30 kg/m2] has been identified in past literature. However, there has been limited data in recent decades. This, along with a dramatic global increase in obesity rates, exposure to environmental and lifestyle risk factors for CRC development, and large updates to the proposed biological mechanisms underpinning this relationship, warrants an updated review of recent data between CRC and obesity.
AIM
To determine if an updated correlation exists between obesity and the risk of CRC development.
METHODS
We evaluated recent data, synthesising pooled estimate effects to determine if an updated correlation exists between obesity and CRC. Observational studies were identified from a range of databases (PubMed, EMBASE, Scopus and the Cochrane database). From the studies identified, sex-stratified meta-analyses were conducted. Additionally, studies included in this review that were unfit for meta-analysis underwent qualitative analysis.
RESULTS
In a pooled sample size of 83506 male participants obtained from six observational studies, a significant positive correlation between obesity and CRC incidence was identified with a hazard ratio (HR) of 1.71 [95% confidence interval (CI): 1.44-2.02]. A pooled sample size of 152043 female participants from six observational studies also revealed a positive correlation with an HR effect of 1.26 (95%CI: 1.03-1.53). Qualitative analysis of studies not included in the meta-analysis consistently supported this relationship for both sexes.
CONCLUSION
Obesity, diagnosed by a BMI ≥ 30 kg/m2, significantly increases the risk of CRC incidence compared to those of a healthy BMI underscoring the importance of focused strategies to prevent obesity as a modifiable risk factor to reduce CRC incidence.
Core Tip: This systematic review and meta-analysis identify obesity as a modifiable risk factor for colorectal cancer (CRC) in both men and women. The risk is further heightened by associated lifestyle factors such as poor diet, physical inactivity, and the presence of comorbidities, including diabetes. These elements contribute synergistically to the development of CRC, highlighting the importance of recognising obesity not just as a health concern but as a cancer-promoting condition. Implementing earlier and targeted screening strategies for CRC in obese individuals can play a key role in reducing incidence and improving outcomes through earlier detection and intervention.
