Disparities in survival among younger breast cancer patients: A SEER database analysis (2000–2021).
Authors: Dharmik M Patel, Adit Dharia, Supriya Peshin, Jahnavi Chaudhari, Nikhil Vojjala, Sakshi Bai, Haik Ser-Manukyan, Grace Kang, Cole Slade, Sanskruti Patel, Salman Muddassir
Journal: Journal of Clinical Oncology (2025)

e13834 Background: Breast cancer is a leading cause of cancer-related mortality, with survival influenced by stage at diagnosis. Early detection improves prognosis, yet ethnic and socioeconomic disparities persist, particularly among patients under 65. This study evaluates survival disparities stratified by stage, focusing on the impact of age, race, and income to inform targeted interventions and health policy reforms. Methods: This retrospective cohort study analyzed 862,290 breast cancer cases in patients aged 20–65 years from the SEER database (2000–2021). Cases were stratified by stage (localized, regional, distant), and survival outcomes were assessed using Kaplan-Meier analysis for median survival and 5-year overall survival (OS). Log-rank tests evaluated subgroup differences. Multivariate Cox proportional hazards models assessed impact of age, race, and income. Disparities were identified by Stage-stratified analyses. Results: The 5-year OS was 94.8% for localized, 85.1% for regional, and 34.6% for distant-stage disease (p &lt; 0.001). Non-Hispanic (NH) Black patients had the worst distant-stage 5-year OS (23.0%), compared to NH White (37.5%) and NH Asian (39.6%) (p &lt; 0.001). Among distant-stage patients, those aged &lt; 35 years had the highest 5-year OS (40.1%), and 50–64 years old had the lowest (31.2%). Also, lower-income patients ( &lt; $50,000) had the lowest 5-year OS (28.8%), while those earning &gt; $100,000 had the highest (38.4%) (p &lt; 0.001). Cox regression models demonstrated significant survival disparities across all stages. Black patients had higher mortality risk (HR: 1.40–1.54, p &lt; 0.001). Older patients (50–64 years) had worse survival compared to younger (HR: 1.14–1.40, p &lt; 0.001). Lower-income patients ( &lt; $50,000) faced worse survival (HR: 1.09–1.24, p &lt; 0.001). Stage-stratified analysis confirmed that these disparities were most pronounced in distant-stage disease, in Black and lower-income individuals. Conclusions: Racial and socioeconomic disparities persist in breast cancer survival among younger patients, particularly in advanced-stage disease. Black patients and lower-income individuals consistently face the worst outcomes. Expanding insurance coverage, improving access to early detection, increasing financial support for underserved populations, and ensuring equitable access to novel therapies are essential to reducing disparities. Systemic policy reforms and targeted interventions are needed to improve survival outcomes equitably. Multivariate cox proportional hazards analysis. Variable Category Localized HR (95% CI) Regional HR (95% CI) Distant HR (95% CI) Age group (yr) vs &lt;35yr 35–49 0.723 (0.682–0.767) 0.783 (0.753–0.814) 1.052 (0.993–1.114) 50–64 1.145 (1.081–1.212) 1.043 (1.005–1.083) 1.397 (1.322–1.476) Race Group vs Hispanic NH Black 1.544 (1.495–1.595) 1.466 (1.428–1.505) 1.401 (1.348–1.455) NH White 0.882 (0.858–0.906) 0.848 (0.829–0.867) 0.939 (0.909–0.971) NH Asian/PI 0.669 (0.639–0.701) 0.771 (0.743–0.801) 0.905 (0.857–0.956) Income group v $50,000–$74,999 &lt;$50,000 1.244 (1.202–1.287) 1.128 (1.095–1.163) 1.088 (1.041–1.137) $75,000–$99,999 0.854 (0.837–0.872) 0.890 (0.873–0.906) 0.916 (0.891–0.941) ≥$100,000 0.712 (0.692–0.732) 0.790 (0.770–0.810) 0.869 (0.838–0.902)