Dealing with the tests for BRCA1 and BRCA2 screening from the clinicians point of view

The two major hereditary breast cancer susceptibility genes, BRCA1 and BRCA2 are associated with 85 to 90% of all hereditary breast and ovarian cancers. They encode for two proteins who participate in a common DNA damage response pathway associated with the double-strand break repair. The standard of gene analysis is complete gene sequencing, although this is a very expensive and time-consuming method. Therefore, it is necessary to select families with a high a-priori risk for having a mutation. Interpretation of gene testing results may be difficult as penetrance is not hundred percent and due to unclassified variants. Prevention of breast and ovarian cancer is possible with prophylactic surgery. Alternatively, endocrine prevention or intensified surveillance could be tried. The evidence of BRCA1 and BRCA2 concerning radiosensitivity is not clear yet. The susceptibility to radiation-induced DNA damage could have implications for therapy options. As the benefits of so far used diagnostic or therapeutic tools are high, they outweigh the possible risks due to increased radiosensitivity. (orig.)