There is an increasing incidence of young breast cancer (YBC) patients with uncertainty surrounding the factors and patterns that are contributing.
We obtained characteristics and survival data from 206,156 YBC patients (≤ 40 years of age) diagnosed between 2005 and 2019 from the National Cancer Database (NCDB). Patients were subdivided into two comparison groups based on year of diagnosis (2005-2009, Old vs. 2015-2019, New group). A Chi-square test of independence was employed to measure the changes. Cox proportional hazards model was used to explore the variables influencing overall survival (OS).
Comparison between Old (55,397 patients) and New groups (67,930 patients) showed an increase in the proportion of Hispanic (8.4% vs 10.0%), Black (16.0% vs 16.6%), and Asian (4.8% vs 6.7%) populations. In the New group, black patients had a significantly worse OS, p < 0.001. Additionally, there was a reduction in the proportion of patients with private insurance (43,940 (81.7%) vs 51,104 (76.4%)) and an increase in patients with Medicaid (5,893 (11.0%) vs 10,694 (16.0%)). Finally, there was a significant increase in hormone positive disease (35,142 (70.0%) vs 49,409 (75.8%), p = < 0.001).
Within YBC patients, the proportion of underrepresented and underserved population is increasing, with an impact on OS. We also see an increase in hormone positive disease. Awareness of these at-risk populations is important for early identification of breast cancer and mitigation of poorer outcomes. Also, there are increasing rates of hormone positive disease which can cause substantial personal and societal implications, such as impacts on family planning and early menopause.

© 2025. The Author(s).