Background: In the United States, breast cancer mortality rates in African American women (AAW) are significantly higher than in European American women (EAW). In contrast, within the Department of Defense Military Healthcare System (DoD MHS) healthcare system, overall survival did not differ significantly between AAW and EAW with early-stage breast cancer. In this study, we evaluated pathological factors of AAW treated within the Murtha Cancer Center at Walter Reed National Military Medical Center to identify factors associated with this lack of disparate outcomes within the DoD MHS. Methods: Between 2001-2018, 345 AAW and 759 EAW treated at MCC/WRNMMC enrolled in the Clinical Breast Care Project (CBCP). Extracted demographic data included BMI, Charlson comorbidity index (CCI), education level and marital and smoking status. All diagnoses were performed by a single breast pathologist and included stage, grade, size, lymph node, hormone receptor and HER2 status. Statistical analyses included odds ratio (OR) and log-rank analyses. Results: Within this cohort, AAW were not at increased risk for having higher CCI scores, cigarette use or a college education, however, AAW were significantly more likely to be obese (OR 2.07, 95% CI 1.5, 2.9) and unmarried (OR 2.4, 95% CI 1.8, 3.2). The average age at diagnosis was 56.1 years in AAW and 57.5 years in EAW with 11% of AAW and 8% of EAW diagnosed <40 years of age. AAW were more likely to have higher stage (OR 1.6, 95% CI 1.3, 2.1), high-grade (OR 2.6, 95% CI 1.9, 3.6), larger (OR 1.6, 95% CI 1.2, 2.1) tumors. AAW were at increased risk for having triple negative tumors (OR 2.1, 95% CI 1.5, 2.9). Neither 5-year nor 10-year survival differed significantly between populations. Conclusion: While a previous study found no overall survival difference in early-stage AAW and EAW treated within the DoD MHS, this study found that across all stages of breast cancer breast cancer-specific survival was not inferior for AAW treated at MCC/WRNMMC. Critically, AAW did not have disparate survival despite having tumors with less favorable pathological characteristics, similar to those seen in the US general population. Evaluation of pre- and post-diagnostic care within DoD MHS should be performed to determine how breast care is provided to AAW within an equal-access healthcare setting and the results used as a model of care template to reduce breast cancer disparities within the US general population. The contents of this publication are the sole responsibility of the author(s) and do not necessarily reflect the views, opinions or policies of Uniformed Services University of the Health Sciences (USUHS), The Henry M. Jackson Foundation for the Advancement of Military Medicine, Inc., the Department of Defense (DoD) or the Departments of the Army, Navy, or Air Force. Mention of trade names, commercial products, or organizations does not imply endorsement by the U.S. Government.

Citation Format: Rachel Ellsworth, Leann Lovejoy, Craig Shriver. Pathologic characteristics of African American women with breast cancer treated at the DoD’s Murtha Cancer Center: Understanding why survival cancer is not disparate to European American women when treated within the US Military Healthcare System [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS7-38.