Hereditary breast cancer: from bench to bedside.
OBJECTIVE
The proportion of breast cancers directly attributable to determinant hereditary factors is estimated to be 5-10%. A number of recent findings with regard to hereditary breast cancer should affect the criteria and scope of routine genetic testing and, soon, breast cancer therapy.


RESULTS
The number of genes causing genetic cancer has expanded, mostly with genes that encode proteins that function in the BRCA1/2 pathways. The risk level associated with some genes is still under investigation, but is high for specific mutations. Some mutant alleles occur frequently, some are rare. High-throughput technologies will progressively allow investigating all genes involved in genetic (breast) cancer risks in all individuals for whom this information could be relevant. This and the emerging novel treatment options specific for cancers in mutation carriers will oblige us to progressively drop all currently used selection criteria such as familial phenotype for genomic testing. A major challenge remains the effective penetration of this knowledge in the professional and lay community, the broad application and financing of this high-throughput technology, and the identification of as yet unknown breast cancer predisposition genes.


CONCLUSIONS
The assessment of breast cancer predisposition genes, previously only an optional predictive genetic test, is growing in importance as it also becomes a therapeutic predictive test.
Medical Oncology, Laboratory of Molecular Oncology, Familial Cancer Clinic, UZ Brussel, Laarbeeklaan, Jette, Belgium. jacques.degreve@uzbrussel.be
Jacques
J
De Grève
Erica
E
Sermijn
Sylvia
S
De Brakeleer
Zhuo
Z
Ren
Erik
E
Teugels
D000465:Algorithms; D000483:Alleles; D001943:Breast Neoplasms / Q000175:diagnosis* / Q000235:genetics* / Q000517:prevention & control; D005192:Family Health; D005260:Female; D019398:Genes, BRCA1; D024522:Genes, BRCA2; D020022:Genetic Predisposition to Disease; D023281:Genomics; D006801:Humans; D008495:Medical Oncology / Q000379:methods; D008957:Models, Genetic; D009154:Mutation; D010641:Phenotype; D011237:Predictive Value of Tests