Clinicopathologic characteristics of triple-negative breast cancer and relationship to basal markers.

e11519 Background: Triple negative breast cancers are immunohistochemical surrogates of basal-like breast cancers. There is no complete overlap between triple negative and basal-like tumors and as gene expression studies evolve, further subclassification bearing clinical relevance is underway. Our purpose was to correlate clinicopathologic characteristics of triple negative breast cancer tumors with expression of basal markers in an effort to define immunohistochemically subgroups of this heterogenous disease Methods: Data were retrieved and analysed using our electronic databank. Patient samples were reviewed by an expert breast cancer pathologist and stained additionally for EGFR and CK 5/6 antibodies. Results: Sixty-five women with triple negative breast cancer were identified. Mean age was 58.3±12.9 years. Most tumors (86%) were of ductal histology, 53% grade 3, 48% having high Ki-67 index (>14%). 10% of patients presented with Stage IV, 25% with Stage III, 38% with stage II and 27% with stage I disea...