Early-onset cancer incidence in the United States by race/ethnicity between 2011 and 2020.

We characterized trends in early onset (aged 20-49) cancer incidence by race/ethnicity and sex using the 2011-2020 Surveillance, Epidemiology, and End Results (SEER) Program dataset. We estimated age-standardized cancer incidence rates, incidence rate ratios (IRR), and annual percentage changes (APC) with 95 % confidence intervals (CI). During the time period examined, cancer incidence increased for female breast (APC: 0.64; 95 % CI: 0.10, 1.20), female colorectal (APC: 2.16; 95 % CI: 1.22, 3.10), and male colorectal (APC: 2.49; 95 % CI: 1.81, 3.19) cancer. Among racial/ethnic groups examined, Hispanic individuals had the largest increases in female all sites (APC: 1.31; 95 % CI: 0.38, 2.25), female breast (APC: 1.04; 95 % CI: 0.29, 1.81), and female (APC: 4.67; 95 % Cl: 3.07, 6.30) and male (APC: 3.53; 95 % CI: 2.58, 4.49) colorectal cancer incidence. Further research is needed to clarify the causal mechanisms driving these patterns.