Patterns in cancer incidence among people younger than 50 years in the United States, 2010 to 2019

Emerging data suggest an increasing incidence of early-onset cancers, defined as cancers diagnosed in people younger than 50 years, but updated data are limited. A cohort study using data from 17 SEER registries from 2010 to 2019, identified 562,145 US patients with early-onset cancer. The incidence rate of early-onset cancers increased substantially over the study period. Breast cancer had the highest number of incident cases and gastrointestinal cancers had the fastest-growing incidence rates among all early-onset cancers.