Rising Incidence and Mortality of Colorectal Cancer Among Younger Adults: A Population-Based Study in Taiwan, 1994-2018.

Colorectal cancer (CRC) incidence and mortality have increased significantly in the Asia-Pacific region over the past three decades. Taiwan is not reported but presents one of the globally highest age-standardized EOCRC incidence and mortality rates. This population-based study in Taiwan from 1994 to 2018 examines changing CRC epidemiology among younger adults (aged 15-29 and 30-49 years) and older adults (aged ≥ 50 years). Age-period-cohort modeling (APC) and average annual percentage change (AAPC) analyses indicated that the elevated risk of age-standardized EOCRC incidence and mortality was primarily driven by the aged 30-49-year-old cohort, whereas only modest increases were observed in adults aged ≥ 50 years. Significant cohort effects were observed in the APC analysis, with annual increases of 3580 and 1000 per 100,000 in incidence and mortality, respectively, among the 30-49-year-old cohort, compared with increases of 2600 and 800 per 100,000, respectively, in the ≥ 50-year-old cohort. Furthermore, participants aged 15-29 years were more frequently diagnosed at stages 3 and 4, resulting in a 7.8% lower survival rate compared with the 30-49-year-old cohort. The key risk factors unique to younger patients with CRC are summarized, highlighting the urgent need for tailored policy interventions.