Racial Disparities in Incidence and Survival of Young Women Diagnosed with Breast Cancer: A Surveillance, Epidemiology, and End Results Analysis

Purpose: Disparities in breast cancer mortality between Black and white women have been well documented. Few studies, however, have examined the interaction of race and clinical characteristics among young breast cancer survivors. This study aimed to enhance the understanding of racial disparities in survival probabilities specific to the young breast cancer population. Methods: : We extracted Surveillance, Epidemiology and End Results (SEER) Research Data for 2000 to 2017 for breast cancer, females, and age 20 to 44 years. We applied Kaplan-Meier curves, Cox proportional hazard regression, and marginal effects analysis after Cox regression. Results: : We analyzed data from 93,491 young breast cancer cases. Notably, compared to non-Hispanic Whites (NHW), non-Hispanic Blacks (NHB) showed significantly higher predicted hazard ratio (HR) values regardless of cancer subtype or stage. NHB with triple-negative subtype had an HR of 11.238 (p=.026) compared to NHW counterparts; NHB with Her2-/HR+ subtype had an HR of 16.599 (p<.001). NHB showed significantly worse cancer-specific survival probabilities than NHW across all stages, with the largest difference in stage IV, with an HR of 95.890 (p=0.001) for NHB compared to NHW. Conclusions: : Our findings revealed that young NHB breast cancer survivors had significantly lower cancer-specific survival probabilities than NHW survivors, even given the same tumor biology and stage, with the lowest survival probabilities among NHB with Her2-/HR+ subtype and higher cancer stage. These findings document significant disparities in survival among young breast cancer survivors and point to avenues for clinical interventions to improve outcomes for all young survivors.