media article: The inherited malignancy of breast cancer (and ovarian cancer)

Note: good article, albeit complicated subject matter - excerpts of important information:

"Dozens of their mutations are associated with an increased risk of hereditary breast and ovarian cancer.....Most recently, huge studies analysing effects of single nucleotide variations in genomic DNA, so-called single nucleotide polymorphisms (SNP), on breast cancer risk of BRCA1/BRCA2 mutation carriers have identified so-called modifier SNP that can decrease or increase the individual lifetime risk......Increased breast cancer risk is also known to be associated with several inherited syndromes, such as Li-Fraumeni syndrome, a condition that is further associated with childhood onset of multiple malignancies including soft tissue sarcomas, leukaemias, and brain tumours....One class contains mutations in genes involved in DNA repair. Their frequency is rather rare and certain mutations can be found only in distinct populations, but this class of susceptibility factors is associated with a moderately increased breast cancer risk. Considering frequency and risk, this class of breast cancer susceptibility factors can be called “rare, intermediate-penetrance mutations”.....he other class involves what are known as “common, low-penetrance variants”. Their biological consequences are mainly unknown, but statistical analyses have shown that they are associated with a significantly increased relative breast cancer risk which, in contrast to the first class, is rather small.....The challenge today is to extract the clinical relevance of these findings and translate them into daily health care. Managing this challenge is crucial if we are to realise the promise of individualized medicine, with intensified surveillance and therapy for high-risk patients and avoidance of unnecessary or even harmful interventions in those with a relatively low risk.

nBrigitte Schlegelberger is professor of Human Genetics and director of the Institute of Cell and Molecular Pathology at Hannover Medical School; Tim Ripperger is a research fellow and trainee in Human Genetics at the Institute of Cell and Molecular Pathology and the Institute of Human Genetics, Hannover Medical School.