¹The Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, Fulham Road, London, UK

Correspondence: Dr NC Turner or Dr JS Reis-Filho, The Breakthrough Breast Cancer Research Centre, Institute of Cancer Research, Fulham Road, London SW3 6JB, UK. E-mail: nicholas.turner@icr.ac.uk, jorge.reis-filho@icr.ac.uk

Abstract

Breast cancers arising in germline carriers of BRCA1 mutations have a characteristic phenotype that has been shown in many studies to differentiate BRCA1 tumours from sporadic tumours. Recently, it has become clear that the characteristic phenotype of BRCA1 tumours is due to expression of the basal-like phenotype. We review these phenotypes, the evidence for BRCA1 pathway dysfunction in sporadic basal-like cancers, and discuss the clinical significance of the basal-like phenotype for cancer genetics and treatment.