Abstract P5-01-13: Flat Epithelial Atypia: Management and outcome in three Dutch teaching hospitals

Background: Flat Epithelial Atypia (FEA) is a presumably neoplastic alteration of terminal duct-lobular units, characterized by the replacement of native luminal epithelium by ductal cells demonstrating low-grade cytologic atypia. The architecture shows stratification of epithelial cells. FEA is often accompanied by microcalcifications and therefore discovered in biopsies following screening mammography. FEA is frequently seen in association with ADH (atypical ductal hyperplasia), DCIS (ductal carcinoma in situ), lobular neoplasia and invasive tubular carcinomas. There is emerging evidence suggesting FEA may represent a precursor to DCIS. The risk of subsequent breast carcinoma remains to be defined. The aim of this study is therefore to inventorise the management and outcome of solitary FEA in histological biopsies in three Dutch teaching hospitals. Materials and Methods: Data of this retrospective multicentre study were collected in a database. Local pathology databases were screened with the terms: ‘FEA’, ‘Flat Epithelial Atypia’, ‘columnar atypia’ and Dutch equivalents. Results were manually screened, only including solitary FEA. Patient files were viewed for information on presentation, mammography, ultrasound and management: surgery vs follow-up. In case of excision, definitive pathology was added. Results: We included 103 patients showing only solitary FEA in the primary biopsy. Management of these patients consisted of follow-up for 60 patients (58,3%) and surgery for 43 patients (41,7%, 49 excisions): lumpectomy (42) or mastectomy (7). Reason for choosing mastectomy was preventive in case of contralateral breast cancer or increased familial or genetic risk. Definitive pathology of lumpectomy or mastectomy showed no abnormalities or solitary FEA in 31 patients; other findings were ADH in 7, LCIS in 4 and DCIS in 7 patients. Some patients showed more than one finding. Invasive breast cancer (IBC) was detected in 3 patients. Only one mastectomy showed invasive disease, located in a different lobe, however. No incidents occurred in the follow-up group. Conclusions: No consistent management exists concerning solitary FEA in these three hospitals. Also, one hospital used the diagnosis of FEA inconsistently and interchangingly with other terms. Lack of this study is the retrospective gathering of data, making it difficult to detect the reasons for the chosen management. DCIS or IBC was discovered in 20,4% of all surgical specimens. It was concluded that FEA should be seen as a red flag, indicating the possible presence of a more malignant lesion. Additional research is warranted concerning long term follow-up for this patient group. Citation Information: Cancer Res 2012;72(24 Suppl):Abstract nr P5-01-13.