Impact of aging on colon cancer burden: A cross-sectional analysis of nationally representative data.

Colon cancer is a major subtype of colorectal cancer and one of the leading causes of cancer-related morbidity and mortality worldwide. Age is a well-established risk factor, yet the precise nature of its association with colon cancer risk - particularly potential nonlinear effects - remains underexplored in large population-based datasets. We conducted a cross-sectional analysis using data from 16,982 adults aged ≥ 18 years who participated in the 2011 to 2018 National Health and Nutrition Examination Survey. Colon cancer status was determined through self-reported medical history. Multivariable logistic regression models were used to assess the independent association between age and colon cancer prevalence, adjusting for sociodemographic, anthropometric, and behavioral covariates. Segmented regression was applied to evaluate potential nonlinear threshold effects. Among 16,982 participants, 117 (0.69%) reported a diagnosis of colon cancer. Age was significantly associated with colon cancer prevalence across all models (adjusted OR = 1.047 per year, 95% CI: 1.032-1.063, P < .001). Subgroup analyses confirmed consistent associations across strata of smoking, diabetes, and hypertension. Segmented regression identified a nonlinear relationship with a threshold at 59 years: below this age, risk increased modestly (OR = 1.030), but rose more steeply thereafter (OR = 1.080). This nationally representative study highlights a strong and nonlinear association between aging and colon cancer prevalence, with a significant risk acceleration after age 59. These findings support the need for age-informed screening strategies and underscore the importance of early intervention and prevention efforts targeted toward older adults.