Approximately 5-10% of all breast cancers have a familial component to it – commonly known as heritability. The majority of breast cancers arise without an apparent cause, what we call spontaneously. Those where a familial component is suspected, will tend to have certain characteristics that are discussed below.
Given that breast cancer is so common, many women are related to or know someone who has been touched by this disease. Often we will see women in the breast clinic concerned about their own personal risk of developing breast cancer.
Familial breast cancer tends to
– present in women at an earlier age
– be associated with other types of cancer – in particular ovarian cancer
– affect multiple members in a family. A common mistake is to assume that only cancers from the mother’s side affect risk. In reality, both the mother and father’s history are relevant. Close relatives diagnosed at a younger age (i.e. sister, mother – are known as first degree relatives, paternal or maternal aunt/grandparent – are known as second degree relative)
– have certain “biological” features – under the microscope, the may look different to common types of breast cancer and also behave differently
Establishing familial breast cancer risk amongst women with breast cancer or healthy women with a family history is important as it may have serious consequences for the rest of the family. In addition, the risk of associated cancers needs to be considered, in particular ovarian cancer.
In May 2013, Angelina Jolie shared her news of carrying a faulty BRCA1 gene and her decision to undergo risk-reducing mastectomy. Since then, genetics clinics around the UK have been inundated with requests for genetic testing and risk-reducing surgery. Genetic testing is a very guarded tool offered to those who are deemed to be at increased risk. Many women not falling into this category may request testing and will ultimately be denied this if they do not fulfil certain criteria of risk. It is important to appreciate that the vast majority of familial breast cancers occur in women with an as yet unidentified genetic mutation.
Several options are available to those who are at risk of familial breast cancer. This will include tablets, risk-reducing surgery and surveillance with appropriate breast imaging. It is important to respect personal choice in this matter as reasons for considering any of the various options may be complex.