Abstract PS4-12-11: Covid-19 and breast cancer disparities: were our fears realized?

Abstract Background: Black women historically present with more advanced stages of breast cancer (BC) and experience 40% higher mortality than White women. The COVID-19 pandemic strained healthcare systems and reduced access to routine care, including screening. These disruptions raised concerns about widening racial disparities in BC diagnosis and treatment. We previously found no significant worsening in stage at diagnosis during the pandemic. Here, we evaluate racial differences in time to first definitive treatment and treatment outcomes before and during the pandemic. Methods: We conducted a retrospective cohort study of self-identified Black and White women aged 18+ diagnosed with invasive BC at a large comprehensive breast center between January 2018 and December 2021. We defined “pre-COVID” as 2018-2019 and “mid-COVID” as 2020-2021. Demographic, clinical, and tumor characteristics, including receptor status (ER, PR, HER2) and clinical stage (AJCC 8), were abstracted from the electronic medical record. Clinical stage was grouped into early (Stage I/II) vs. late (Stage III/IV). Time to first definitive treatment (surgery or chemotherapy) was calculated from diagnosis, with delay defined as 60 days. Neighborhood-level social vulnerability was derived from census tract data. Chi-square, Wilcoxon, and logistic regression analyses were used to assess associations by race and time period. Results: Of 3,399 patients, 10.4% were Black and 89.6% White. Black patients were more likely to live in urban areas (61.3% vs. 13.7%, p0.0001), have public insurance (56.9% vs. 43.0%, p0.0001), and reside in distressed communities (28.2% vs. 9.9%, p0.0001). Compared to White women, Black women were more often diagnosed with Stage II disease (25.1% vs. 15.2%, p0.0001) and had a higher prevalence of hormone receptor-negative tumors (ER-negative: 29.5% vs. 17.3%, PR-negative: 42.9% vs. 26.8%; both p0.0001).Black women had a longer median time to first treatment compared to White women (48 vs. 43 days, p=0.05) and were more likely to experience treatment delays of 60 days or more (34.9% vs. 26.8%, p=0.01). The distribution of diagnoses across the pre- and mid-COVID periods did not differ significantly by race. In the pre-COVID period (2018-2019), 56.4% of Black patients and 56.3% of White patients were diagnosed, compared to 43.6% and 43.7%, respectively, in the mid-COVID period (2020-2021; p=0.97). Conclusion: Black patients experienced longer delays to first BC treatment and lower treatment rates compared to White patients in both the pre-COVID and mid-COVID periods. Our findings suggest that racial disparities in timely treatment persisted but were not amplified by the COVID-19 pandemic. Ongoing analyses will assess associations between these delays and outcomes such as recurrence and mortality. Citation Format: R. Rumano, R. Andrea, V. Heh, A. Clark, E. Paskett, B. Oppong. Covid-19 and breast cancer disparities: were our fears realized? 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 PS4-12-11.