The pathology of inherited breast cancer

Familial breast cancer has been recognised for many years. In the 1990s the genetic mechanism of inheritance of a proportion of these familial cancers was found to be attributable to germline mutation in either of two newly discovered genes, namely BRCA1 and BRCA2. Since the discovery of these genes, studies have been performed in which the pathological characteristics of familial cancers arising in patients with germline BRCA1 and BRCA2 mutation have been examined. A distinct pathological phenotype of high-grade, oestrogen receptor-negative breast cancer, often with medullary features, has been consistently described for BRCA1 cancers. A less distinct phenotype has been described for BRCA2 cancers. The discovery of genotype-phenotype correlation has significant implications for patient management and novel treatment strategies, not only for inherited cancers, but for breast cancer in general.