Five to ten per cent of all breast carcinomas are of hereditary origin.
Many of them have been associated to mutations in the BRCA1 and BRCA2 susceptibility genes. No �BRCA3�
gene has been found to account for the non-BRCA1/BRCA2 breast cancer (BRCAx) families, and BRCAx tumors
are increasingly believed to originate from multiple distinct genetic events. Phenotype studies have
questioned the existence of specific �portraits� among hereditary breast carcinomas (HBC). They have shown
that most BRCA1 tumors have a �basal (epithelial)-like� aspect, while BRCA2 and BRCAx HBC are more
heterogeneous. HBC have also been submitted to genetic analyses, notably with the objective of resolving
the heterogeneity of BRCAx lesions. The present review aims to summarize recent data on BRCA1, BRCA2, and
BRCAx HBC, including hypotheses on the origin of BRCA1 tumors and their paradoxical relations to
estrogen-sensitivity.
BreastMed Consortium: Yves-Jean Bignon, Nancy Uhrhammer, Unit� d'Oncog�n�tique, Centre Jean Perrin,
Clermont-Ferrand, France; Nathalie Zammatteo, Jos� Remacle, URBC, Fondation Universitaire Notre-Dame
de la Paix, Namur, Belgium; Andr� M�garban�, Unit� de G�n�tique M�dicale, Universit� Saint-Joseph,
Beirut, Lebanon; Nourredine Ben Jafaar, Abdelaziz Sefiani, Institut National d'Oncologie, Rabat, Morocco;
Lotfi Chouchane, Sami Remadi, Laboratoire d'Immuno-Oncologie Mol�culaire, Monastir, Tunisia; Amel Ben
Ammar-El Gaaied, Laboratoire de G�n�tique Mol�culaire, d'Immunologie et de Biotechnologie, Facult� des
Sciences de Tunis, Tunis, Tunisia; Denis Larsimont, Jean-Marie Nogaret, Institut Jules Bordet, Bruxelles,
Belgium; Catherine Sibille, Christine Galant, Centre de G�n�tique M�dicale, Universit� Catholique de
Louvain, Bruxelles, Belgium; Fran�oise de Longueville, Eppendorf Array Technologies (EAT), Namur,
Belgium; V�ronique Vidal, Diagnog�ne, Aurillac, France.
