title: Histopathology of BRCA1- and BRCA2-associated breast cancer.
abstract: Hereditary breast carcinomas that are attributable to BRCA1/2 mutations have their own morphological and immunohistochemical characteristics. BRCA1-associated carcinomas are poorly differentiated infiltrating ductal carcinomas that frequently show morphological features of typical or atypical medullary carcinoma. BRCA2-associated breast carcinomas tend to be of higher grade than sporadic age-matched controls. BRCA1tumors have been found to be more frequently estrogen receptor- and progesterone receptor-negative, and p53-positive than are age-matched controls, whereas these differences are not usually found in BRCA2-associated tumors. In addition, BRCA1- and BRCA2-associated breast carcinomas show a low frequency of HER2 expression. Most BRCA1 breast carcinomas are characterized by the expression of basal (myoepithelial) markers, such as cytokeratin 5/6 and or P-cadherin. These features could be used to distinguish patients who are likely to carry a BRCA1 or BRCA2 germline mutation, thus indicating which gene should be screened for first in families with a high incidence of breast and ovarian cancer.
authors.affiliation: Human Genetics Department, Centro Nacional de Investigaciones Oncológicas (CNIO), Madrid, Spain.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Honrado
authors.forename: Javier
authors.initials: J
authors.lastname: Benítez
authors.forename: José
authors.initials: J
authors.lastname: Palacios
mesh_terms: D001943:Breast Neoplasms / Q000235:genetics / Q000473:pathology*; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D006580:Genetic Carrier Screening; D006801:Humans; D009154:Mutation; D009693:Nucleic Acid Hybridization; D020411:Oligonucleotide Array Sequence Analysis