Recent trends in Early-Onset cancer incidence rates

The increasing incidence of early-onset cancers is a growing concern. Using newly released Surveillance Epidemiology and End Results (SEER) data incorporating 2023 incidence rates, we evaluated emerging trends by comparing 5-year average annual percent changes (AAPC) in incidence rates for 2018-2022 and 2019-2023 across the 22 most common cancer types in individuals under 50 years of age. The AAPC changed significantly for liver and intrahepatic bile duct cancer from 2.6% (non-significant) in 2018-2022 to 3.7% (increasing) in 2019-2023. For non-Hodgkin lymphoma and lung and bronchus cancer, AAPCs changed from -0.5% to 1.1% and from -2.0% to 0.3%, respectively (decreasing to non-significant). A continuous increase in incidence rates was observed for cancers including but not limited to colorectal cancer (excluding appendix) and ovarian cancer. These findings underscore the need for robust cancer registry data to support surveillance research and inform prevention and control efforts in younger populations.