Clinico-Pathological Characteristics of Triple Negative and Non Triple Negative High Grade Breast Carcinomas with and Without Basal Marker (CK5/6 and EGFR) Expression at a Rural Tertiary Hospital in India

UNLABELLED Aims of the study were to evaluate the expression Cytokeratin 5/6(CK5/6) and Epidermal Growth Factor Receptor (EGFR) among triple negative breast cancers and high grade infiltrating duct carcinomas. Further to probe if triple negative phenotype can be a surrogate marker for basal phenotype and to correlate the expression of basal markers with disease free survivals among triple negative phenotype and high grade infiltrating duct carcinomas. METHODS Expression of CK5/6 and EGFR were studied by Immunohistochemistry (IHC) in 31 triple negative and 19 non-triple negative high grade breast carcinomas. RESULTS 21 of the 31 triple negative phenotype (67.7%) breast carcinomas and 7 out of 19 non-triple negative (36.8%) breast carcinomas showed expression of basal markers (CK5/6 and/or over-expression of EGFR). There were statistically significant associations of all the basal-like tumors with negative hormonal status. The basal markers positive phenotype subjects had a shorter disease free interval as compared to basal markers negative phenotype subjects. CONCLUSION Basal-like breast carcinomas constitute a unique clinical and pathological entity, characterized by high tumor grade and a propensity for lack of ER, PR and HER2 expression. Basal phenotypes have a more aggressive course than non-basal phenotype. "Triple negative" status cannot be used as a surrogate for "basal marker expression".