Abstract PS4-11-21: Breast Cancer Trends and Outcomes Among Young Hispanic and Asian/Pacific Islander Women Age < 40 in the National Cancer Database (NCDB) adjusted for U.S. population data

Abstract Background Breast cancer incidence is rising nationally, particularly among young women. While many studies have documented the rising incidence in Black women, few studies have investigated these trends in Asian/Pacific Islanders (API) and Hispanic women. The primary objective of this study was to analyze trends in the incidence of breast cancer in API and Hispanic women under forty years old adjusted for U.S. population data. Methods This study employed a retrospective cohort design to analyze trends in breast cancer diagnoses among women under and over forty years of age from 2010 to 2022 using data from the National Cancer Database (NCDB). The NCDB was queried for women diagnosed with breast cancer from 2010-2022. Patients were stratified by age < 40 and age > 40 at time of breast cancer diagnosis. Breast cancer incidence data from the NCDB were analyzed using U.S. Census data population estimates. Results: Of 4,195,384 women (mean age 61±13), 188,311 were under 40 and 4,007,073 were over 40. Among women with breast cancer under age forty, 63.5% were White, 16.4% Black, 11.2% Hispanic, 6.3% API, and 2.6% Non-Hispanic Other. In contrast, in women with breast cancer diagnosed at age ≥40, a larger majority (77.5%) were white with lower proportions of Black (11.3%) and Hispanic (5.6%) patients. Women age < 40 were more likely than women age > 40 to have human epidermal growth factor-2 negative (Her2-) breast cancers (16.2% vs 8.1%) and triple negative breast cancers (TNBC) (12.8% vs 6.6%). Women age < 40 were also more likely than women age > 40 to be diagnosed with grade 3 tumors (50.8% vs 28.7%), Stage III-IV disease (20.0% vs 11.1%), and be treated with chemotherapy (70.5% vs 31.0%). From 2010 to 2022, incidence in young women rose 15.4% in all races/ethnicities. Broken down by subgroup, the incidence rose 19.9% in white, 5.3% in black, 27.7% in Hispanic and 18.9% in API women. These findings confirm an increase in incidence rates among young women across all racial/ethnic groups. Our study shows the greatest relative increase in breast cancer rates in young Hispanic women and Black women experiencing the lowest relative increase. Conclusions: This study examined trends and outcomes in young minority women diagnosed with breast cancer age < 40. Hispanic women < 40 experienced the highest rise in incidence at 27.7% over 14 years followed by API women < 40 with 18.9% rate of incidence. The dramatic increase in breast cancer incidence among young women of color, particularly Hispanic and API women, is notable and warrants further research into factors contributing to these disparities. Citation Format: P. Saha, K. Kuchta, D. Thompson, K. A. Yao. Breast Cancer Trends and Outcomes Among Young Hispanic and Asian/Pacific Islander Women Age < 40 in the National Cancer Database (NCDB) adjusted for U.S. population data [abstract]. In: Proceedings of the San Antonio Breast Cancer Symposium 2025; 2025 Dec 9-12; San Antonio, TX. Philadelphia (PA): AACR; Clin Cancer Res 2026;32(4 Suppl):Abstract nr PS4-11-21.