Body Roundness Index and Incident Colorectal Cancer Risk: A Nationwide Population-Based Cohort Study

Area of Science:

• Oncology
• Epidemiology
• Public Health

Background:

• Colorectal cancer (CRC) is a leading cancer in Korea.
• Visceral adiposity is a known modifiable risk factor for CRC.
• Body roundness index (BRI) offers a more accurate visceral adipose tissue estimate than body mass index (BMI).

Purpose of the Study:

• To investigate the longitudinal association between BRI and incident CRC in a large Korean national cohort.
• To evaluate BRI as a potential tool for CRC risk stratification.

Main Methods:

• Utilized a nationwide cohort of 4,492,697 Korean adults (≥20 years) from 2012 to 2023.
• Employed Cox proportional hazards regression, adjusting for multiple covariates and applying a 1-year lag period.
• Conducted subgroup and site-specific analyses to explore variations in the association.

Main Results:

• A significant, independent, and dose-dependent association was found between higher BRI and increased CRC risk (Q4 vs. Q1: aHR 1.104).
• The association was markedly stronger in men (Q4 aHR 1.352) compared to women (Q4 aHR 0.891).
• A proximal-to-distal gradient was observed for CRC sites: proximal colon, distal colon, and rectum.

Conclusions:

• Elevated BRI is independently associated with higher CRC incidence in Korean adults.
• BRI may serve as a valuable complement to BMI for assessing CRC risk, especially in populations with high metabolic obesity.
• The findings highlight the importance of visceral adiposity in CRC development, particularly in specific demographic groups.