Fehmi, RA

Abstract Invasive breast carcinoma in African American (AA) women differs significantly from their Caucasian (CA) counterparts in its incidence, morphology and outcome. These tumors are more likely to be high grade, hormone receptor negative, present at a younger age and at a higher stage. Evaluation and a better understanding of precursor lesions may help delineate the mechanisms underlying the development of breast cancer in these two groups. Atypical hyperplasia (AH) in the breast has been associated with an increased risk of developing cancer (relative risk∼4.0). Risk stratification of these women by identification of predictive biomarkers would be beneficial for optimal patient care. In our study we evaluated the expression of the following prognostic biomarkers: estrogen receptor (ER), Cyclooxygenase-2 (COX-2) enzyme and Ki-67 in AH in a cohort of AA women with benign breast biopsies. AA women with benign breast biopsies from years 1997–2000 were retrieved from our departmental database. Clinical and follow up data was obtained from the SEER database. The hematoxylin and eosin (H & E) slides for these cases were reviewed by 2 pathologists, who were blinded to the outcome, and those with atypia were included in this study. Paraffin blocks were retrieved for immunohistochemical (IHC) analysis and standardized scoring methods applied. A total of 1608 AA women had benign breast biopsies during the study period. We performed IHC analysis on 37 (2.3%) who were diagnosed with atypia (25 cases of atypical ductal hyperplasia (ADH) and 12 cases of atypical lobular hyperplasia (ALH)). Increased COX-2 expression was seen in 19 of 28 (67.8%) cases with AH. Of these, 13 of 19 cases (68.4%) were of ADH and 6 of 9 cases (66.7%) were of ALH. Twenty of 25 cases had a high expression of ER overall. Of these, 15 of17 (88.2%) of the positive cases was in the ADH category and 3 of 7 (42.8%) was in the ALH group. Of 32 cases, only 3 cases showed a proliferation rate of > 2% (9.4%) with Ki-67 IHC stain. All of these cases belonged to the ADH (21) category. In summary, the majority of AH cases showed increased COX-2 expression, although no differences were observed between lobular and ductal lesions. In contrast, ADH lesions appeared to exhibit increased reactivity for ER compared to ALH. Similarly, although rare, more ADH cases showed an increased proliferation rate compared to ALH. From our data, COX-2 and ER might be of prognostic significance in AA patients with AH. Larger studies with follow up are needed to understand this disease further. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P2-11-07.

Abstract African American (AA) women have higher mortality rates from breast cancer (BrCa) and are diagnosed at younger ages than their Caucasian counterparts. Women who have had a benign breast biopsy are at increased risk of the disease, although less is known about the risk of BrCa associated with benign breast disease in AA women. We examined 1428 breast biopsies from AA women which occurred from 1997–2000 and assessed various pathologic markers including: apocrine metaplasia, ductal hyperplasia including atypia, evidence of cysts, duct ectasia, fibrosis, intra-ductal papilloma, sclerosing adenosis, columnar alteration, and involution (atrophy). These women were followed for later BrCa through the Metropolitan Detroit Cancer Surveillance System, part of the Surveillance, Epidemiology and End Results (SEER) program through 2008. Women who developed BrCa were compared to those in the cohort who did not, and to other AA women with BrCa in the SEER registry. AA women in our study were also compared to Caucasian women in the Mayo Clinic cohort. Differences in variables were assessed by chi-squared tests and 95% confidence intervals. Of the 1428 biopsies, 52 (3.6%) subsequent incident breast cancers were reported in SEER. The mean age at diagnosis was 59, and the mean time from biopsy to BrCa diagnosis was 6.1 years. Individuals with atypical ductal hyperplasia at biopsy (n=37, 2.6%) were more likely to develop breast cancer (n=7, 13.5%, p<0.01). No other pathologic variables were associated with increased risk. Women in our cohort with breast cancer did not differ from AA in the SEER database with respect to age at diagnosis, stage at diagnosis, or receptor positivity. Compared to the Caucasian women in the Mayo Clinic BBD cohort, AA women in our study were younger at biopsy (p<0.01), but had similar percentages of involution and atypia (p=0.50 and 0.15, respectively). Our preliminary findings among a relatively small group of AA women with prior benign breast biopsies and incident breast cancers suggest that results from the Mayo Cohort study are likely to apply to AA populations. Citation Information: Cancer Res 2011;71(24 Suppl):Abstract nr P1-08-16.