Introduction: Incidence of breast cancer is higher in young African American (AAW) compared to Caucasian women (CW) and is frequently associated with an aggressive phenotype and poor clinical outcome. These differences have often been attributed to differences in access to quality-health care. The Clinical Breast Care Center at Walter Reed Army Medical Center provides high-quality equal-access breast care to military personnel and their dependents. Clinical and pathological factors, including tumor stage, ER, PR and HER2 status and outcome, were examined in AAW and CW patients with invasive breast carcinomas. Methods: AAW (n=76) and CW (n=253) with invasive breast cancer were enrolled in the Clinical Breast Care Project (CBCP). Clinical was collected using a large 500-field questionnaire and every specimen was reviewed by a single dedicated breast pathologist. ER, PR and HER2 protein levels were determined by IHC and/or FISH analysis. Data was analyzed patients from patients with invasive breast cancer using Student’s t-test and exact unconditional tests. Results: The average age of diagnosis was significantly lower (P<0.01) in AAW (mean =51 yr) compared to CW (mean = 59 yr), with 14% of AAW diagnosed under age 40 compared to 5% of CW. Stage at diagnosis, lymph node and HER2 status did not differ between the two groups. Significantly more tumors from AAW were ER negative (33% v 21%; P<0.05), PR negative (55% v 30%; P<0.0001) and had the triple negative phenotype (ER, PR, and HER-2/neu negative; 18% v 6%; P<0.005). The mortality rate was significantly higher in AAW (6% v 1.5%; P<0.05) compared to CW. Conclusions: A reported higher stage at diagnosis in AAW has been suggested to reflect delays in seeking medical treatment, suggesting that poor outcomes in AAW with breast cancer are associated with socioeconomic factors; however, in this population, provided with high-quality health care regardless of the ability to pay, while stage at diagnosis did not differ between AAW and CW, tumors from AAW were associated with poor pathological characteristics and higher mortality rates. Pathological and phenotypic differences between AAW and CW suggest that invasive breast tumors are different biological diseases, associated with population-specific molecular profiles.
99th AACR Annual Meeting-- Apr 12-16, 2008; San Diego, CA