ABSTRACT
Individuals with a family history of breast and ovarian cancer are often seen in cancer
genetics clinics, as they are worried about their chances of developing these and other
types of cancer. Clinical management of these individuals involves assessment of the
degree of risk due to the family history, often in conjunction with genetic testing. The
first risk estimation to be made is the chance that a familial cluster is due to genetic
predisposition. This is called the prior probability of a cancer predisposition gene
being present in a family. This estimation can be based upon published data or
clinical experiences when published data are lacking, which unfortunately is often the
case with rare genetic conditions. In the case of hereditary breast and ovarian cancer,
however, we are in the fortunate position of having several risk prediction models.
The primary function of these is to try to evaluate the prior probability of a high-risk
gene being present in the family. The second part of risk evaluation in the cancer
genetics clinic is the risk that a specific individual will go on to develop a
malignancy. This is also facilitated by some, but not all, of the risk prediction models
currently available.
