Divergent age-specific trends in colorectal cancer mortality: A 22-year analysis of the emerging early-onset crisis.

Abstract

e15722 Background: Despite overall improvements in colorectal cancer (CRC) outcomes, concerning trends have emerged in younger populations. We examined two decades of US mortality data to characterize age-specific trajectory differences and identify inflection points in the epidemiologic landscape of CRC. Methods: Using CDC WONDER data (1999–2020), we analyzed age-adjusted CRC mortality rates (ICD-10: C18–C20) stratified by age: early-onset (≤44 years) versus late-onset (≥45 years). Joinpoint regression analysis (Version 5.4.0.0) with permutation testing identified significant trend changes. Annual Percent Change (APC) estimates with 95% confidence intervals assessed temporal patterns, with statistical significance set at α = 0.05. Results: Late-onset CRC (≥45 years): Mortality rates declined substantially from 69.26 to 40.49 per 100,000, representing a 41.6% reduction. A critical inflection point occurred in 2014 (95% CI: 2011–2015), marking a deceleration in the rate of improvement. The pre-2014 period showed robust decline (APC: −3.06%; 95% CI: −3.18 to −2.93; p < 0.000001), which slowed significantly post-2014 (APC: −1.61%; 95% CI: −2.12 to −1.09; p = 0.000006)—a 47% reduction in the pace of mortality improvement.Early-onset CRC (≤44 years): In stark contrast, mortality rates increased from 0.92 to 1.13 per 100,000, representing a 22.8% rise. No inflection points were identified; instead, a persistent upward trajectory characterized the entire 22-year period (APC: +0.78%; 95% CI: +0.54 to +1.02; p = 0.000001). This yielded a continuous, unabated increase in deaths among young adults. Conclusions: This analysis reveals a troubling paradox in US colorectal cancer mortality: while older adults experienced substantial but decelerating improvements, young adults faced steadily worsening outcomes throughout the study period. The 2014 inflection point in older adults, coinciding with slowed screening expansion and potential changes in risk factor prevalence, coupled with the relentless rise in early-onset mortality, signals an urgent need to reassess prevention strategies, lower screening age thresholds, and investigate biological and environmental drivers of early-onset disease. The nearly 23% increase in mortality among those ≤44 years represents a growing public health crisis demanding immediate action.