Triple negative, basal-like and BRCA1 associated breast cancers – what’s the difference and should anyone care?
Breast carcinoma is common in women and forms an integral part of the BRCA familial cancer syndromes. As breast cancer is considered a heterogeneous disease, clinicians have traditionally relied on clinical and morphologic findings, as well as hormone receptor/HER-2 status for prognostic and predictive categorisation of tumours. Recently, breast cancer subclassification has been aided by the discovery of various gene expression profiles, compiled after simultaneous examination of multiple tumour biomarker genes. Basal-like breast cancer was delineated using this methodology and demonstrates significant overlap with so-called triple negative and BRCA1-associated breast carcinomas. This article describes the pathology and biology of these three groups of tumours and examines the relationship between them. Therapeutic implications are also briefly discussed.