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Hereditary breast cancer: an update on genotype and phenotype.
par Marc Lacroix & Guy Leclercq
Laboratoire Jean-Claude Heuson de Cancérologie Mammaire, Institut
Jules Bordet, Bruxelles, Belgique et InTextoResearch, Baelen, Wallonie,
Belgique.
dans New Breast Cancer Research, Nova Sciences Publishers, ISBN
1-59454-932-X (2006) pp27-51.


http://www.geocities.com/m.lacroix/livre4.htm

A significant minority (5-10%) of breast carcinomas is considered of
hereditary origin. Part of them is associated to mutations in the BRCA1
and BRCA2 susceptibility genes, which have been extensively studied.
For their part, tumours in the non-BRCA1/BRCA2 breast cancer (BRCAx)
families are increasingly believed to originate from multiple genetic
events, as no "BRCA3" gene has been identified. The existence of
specific "portraits" among hereditary breast carcinomas (HBC) has been
questioned. Phenotype studies have shown that most BRCA1 tumours are
part of a "basal epithelial-like" group of lesions. In contrast, BRCA2
and BRCax HBC are more heterogenous, as also observed with sporadic
carcinomas. Genetic analysis has also been applied to HBC, notably with
the objective of resolving the heterogeneity of BRCAx lesions. This
chapter aims to summarise recent data on BRCA1, BRCA2, and BRCAx HBC,
and to provide hypotheses on the origin of BRCA1 lesions, their
high-frequency of P53 mutations, and their paradoxical relations to
oestrogen-sensitivity.