Colorectal cancer in young adults: What social behavior factors may be responsible?

e15706 Background: The incidence of colorectal cancer (CR) is rising amongst younger individuals in the United States. We proposed to evaluate the trends in obesity and physical activity associated with colorectal cancer incidence in the U.S. Methods: Cancer incidence was extracted from the United States Cancer Statistics Public Use Database (USCS). Obesity based on BMI was obtained from the National Health and Nutrition Examination Survey (NHANES) and physical activity level defined as > 150 min/week was gathered from the National Health Interview Survey (NHIS). The Joinpoint Regression Program (National Cancer Institute) and chi-squared tests were used for statistical analyses. Results: Using the NHANES database from 2001 - 2020, the overall incidence of obesity has increased by over 43% across the United States (23.8% to 34.1%, p < 0.001). More specifically, the incidence of obesity in younger (19 - 54 years old) adults observed the largest increase of over 39% (30% to 41.8%, p < 0.001). Although Black individuals had the highest rate of incidence of obesity at 39.8% in 2020, Hispanic adults saw the largest overall increase of over 55% in the last 20 years (21.9% to 34%, p < 0.001). Using the NHIS dataset, we studied the rate of physical inactivity across the United States in 2022. Overall, 46.6% of adults have inadequate physical activity in their lifestyle. Moreover, the rates of physical inactivity were significantly higher in Hispanics compared to Whites (53.2% vs. 44.1% p = 0.022). Adults in the South had the highest rates of inactivity at 49.3% compared to other geographic areas. The intersection of Hispanic females had the highest rate of physical inactivity at 58.2% (p < 0.001) compared to other groups studied. Based on USCS, early-onset ( < 55 years old) colorectal cancer incidence has increased in the last 20 years, in contrast to decreasing rates amongst older individuals. More specifically, younger (20-24 years) adults had one of the highest annual increases at 4.56% (p < 0.001). Furthermore, our intersectional analysis found that Hispanic females aged 30-34 residing in the West had one of the highest annual increases at 4.82% in the last 20 years (p < 0.001). Conclusions: Colorectal cancer is increasing in younger adults, specifically in young Hispanic females. Trends in social determinants of health such as obesity and physical inactivity may partially explain these findings.