Observational Study
Copyright ©The Author(s) 2025. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Oncol. Jul 24, 2025; 16(7): 108220
Published online Jul 24, 2025. doi: 10.5306/wjco.v16.i7.108220
Obesity as a risk factor for early-onset colorectal cancer: Evidence from a nationally representative database
Omar Khattab, Mohamed Alharami, Frhaan Zahrawi, Ammar Hemaidan
Omar Khattab, Department of Internal Medicine, Kettering Health Network, Kettering, OH 45429, United States
Mohamed Alharami, Department of Internal Medicine, Henry Ford Warren, Warren, MI 48093, United States
Mohamed Alharami, Department of Gastroenterology, Advanced Medical Research Center, Port Orange, FL 32127, United States
Frhaan Zahrawi, Department of Internal Medicine, Franciscan Health Olympia Fields, Chicago, IL 60461, United States
Ammar Hemaidan, Department of Gastroenterology, Florida State University, Daytona Beach, FL 32114, United States
Author contributions: Khattab O designed the study, collected data, and wrote the paper; Alharami M conducted literature review and assisted in writing introduction and discussion; Zahrawi F extracted data using R, assisted with statistical analysis, and wrote materials and methods section; Hemaidan A supervised the project, provided feedback and proofreading of the manuscript.
Institutional review board statement: The Kettering Health Institutional Review Board has determined this project does not meet the definition of human subject research according to federal regulations, and therefore does not fall under the purview of the IRB.
Informed consent statement: Per NHANES protocols, participants were given written informed consent.
Conflict-of-interest statement: Dr. Khattab has nothing to disclose.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Data sharing statement: sharing statement: Technical appendix, statistical code, and dataset is available from the corresponding author.
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: Omar Khattab, MD, Department of Internal Medicine, Kettering Health Network, 3535 Southern Boulevard, Kettering, OH 45429, United States. omar.khattab@ketteringhealth.org
Received: April 17, 2025
Revised: May 8, 2025
Accepted: June 7, 2025
Published online: July 24, 2025
Processing time: 96 Days and 16.2 Hours
Abstract
BACKGROUND

Colorectal cancer (CRC) is the second leading cause of cancer-related deaths worldwide with an alarming rise in early-onset CRC (eoCRC) over the past several decades. Unlike late-onset CRC, the drivers behind eoCRC remain less clear. While certain risk factors such as obesity and smoking have demonstrated a relatively strong association with eoCRC in the literature, some studies have challenged these associations, emphasizing the need for additional studies.

AIM

To investigate the impact of various risk factors on eoCRC with a special focus on obesity.

METHODS

This cross-sectional study used de-identified data from the National Health and Nutrition Examination Survey (1999-2023), including 30321 United States adults aged 18 to 49 years. Participants with missing key variables were excluded. Standardized protocols were used to collect demographic, lifestyle, anthropometric [body mass index (BMI), body roundness index (BRI), waist circumference (WC)], and self-reported CRC data. Logistic regression and propensity score matching assessed associations between obesity-related parameters and eoCRC. Statistical analyses were performed in R and Stata, with P < 0.05 defined as significant.

RESULTS

Of 30321 participants, 48 received a diagnosis of eoCRC. Patients with eoCRC were older (mean age 39.96 years vs 34.36 years; P < 0.001) and had higher WC and BRI. None of the eoCRC patients were heavy drinkers (P = 0.006). Unadjusted models demonstrated significant associations of eoCRC with BRI quartiles, as well as BMI-defined obesity, WC, and smoking. In unadjusted models, BRI remained the strongest independent predictor; those in the highest BRI quartiles had over 10-fold greater odds of eoCRC. In fully adjusted models, BRI remained significant, but BMI- and waist-based obesity were not.

CONCLUSION

BRI is a stronger predictor of eoCRC risk compared to other obesity indices and is a superior tool for identifying young individuals at higher risk of CRC.

Keywords: Early-onset colorectal cancer; Obesity; Body roundness index; Body mass index; Waist circumference; Risk factors; Logistic regression; Propensity score matching

Core Tip: Early-onset colorectal cancer (CRC) is rising globally, yet its modifiable risk factors remain unclear. This cross-sectional study analyzed over 30000 United States adults aged 18-49 using the National Health and Nutrition Examination Survey data (1999-2023) to assess the relationship between obesity and early-onset CRC (eoCRC). Among multiple obesity indices, body roundness index (BRI) emerged as the strongest predictor of eoCRC risk—even after adjusting for body mass index, waist circumference, and lifestyle factors. BRI offers a more holistic assessment of body fat distribution, making it a potentially superior screening tool for young adults at higher risk for CRC.