Factors Associated With Hospitalization Among Breast Cancer Patients With COVID-19: A Diverse Multi-Center Los Angeles Cohort Study

We investigated outcomes of 132 patients with breast cancer and SARS-CoV-2 infection at two Los Angeles health systems. In this study, older age and more comorbidities were associated with COVID-19 hospitalization and death, while Hispanic/Latinx ethnicity was associated with hospitalization. Breast cancer therapies were not associated with hospitalization or death from COVID-19 in our cohort; larger studies are needed to further explore these relationships. Background: The SARS-CoV-2 virus has infected and killed millions of people worldwide. Breast cancer is the most prevalent cancer in women and few studies have investigated the outcomes of patients with a history of breast cancer and COVID-19. We report the clinical outcomes of patients with invasive breast cancer who tested positive for SARSCoV-2, including hospitalization and death, and evaluate demographic and cancer-related factors associated with these outcomes.Patients: Patients with a history of invasive breast cancer and positive SARS-CoV-2 test from January 1 to December 31, 2020 at two large, academic Los Angeles health systems were included. Methods: Retrospective chart review of the electronic medical record was performed. Data for demographic and cancer-related factors were manually abstracted. Relationships between outcomes and clinical variables were evaluated using Fisher's exact test and linear regression analysis. Results: Among a total of 132 patients, 40 (30.3%) were hospitalized, while 11 (8.3%) required intensive care support, and 8 patients (6.1%) died. Older age and presence of one or more additional comorbidities were associated with hospitalization and death ( P = .010, P = .003, P = .034, P < .001). Hispanic/Latinx ethnicity was associated with hospitalization ( P = .047). Cancer treatment was not associated with hospitalization or death. Conclusion: In our diverse, multi-center, breast cancer cohort, Hispanic/Latinx ethnicity, older age and presence of other comorbidities were associated with worse outcomes from COVID-19. Breast cancer treatment, including surgery, radiation, systemic therapy, and endocrine therapy, was not associated with hospitalization in our cohor t. Fur ther studies are needed to explore the relationship between breast cancer and COVID-19 outcomes.