Actress Angelina Jolie has today written an op-ed in The New York Times explaining that she has opted to have a double mastectomy because she carries the hereditary BRCA1 gene, which she says increases her risk of breast cancer by 87%. Her mother died from breast cancer after a ten-year struggle at the age of 56.
We asked an expert in breast cancer and genetics to explain more about the breast cancer genetic mutation and what it means for women.
What are the BRCA1 (and BRCA2) gene mutations?
BRCA1 and BRCA2 are genes that have been linked to hereditary breast and ovarian cancer. Women who inherit one of these faulty genes are at an increased risk of breast or ovarian cancer. Men who inherit a faulty gene may be at increased risk of prostate cancer. Breast cancer in men carrying BRCA2 has also been described in the medical literature.
These genes are important in helping repair breaks in the DNA in our cells, so a faulty gene can mean that DNA repair is less than optimal. In some people this can lead to the development of cancer.
Should I be getting tested for them?
Not routinely. In general terms, genetic testing should be carried out following counselling in a familial cancer centre after a proper assessment of risk.
Testing is offered to people who have developed breast or ovarian cancer where there are features that might suggest a mutation is present.
These can include an early age of onset of cancer, or cancer in both breasts, multiple cancers in the family, male breast cancer, ovarian cancer, certain ancestry (such eastern European Jewish ancestry), or where there is a known mutation in the family.
Sometimes the appearance of a tumour, reported by the pathologist can help make a decision regarding whether testing is necessary.
How are they tested for?
This is generally done through a blood sample.
What is the cost of the test/s and why?
At present testing for these genes in Australia is expensive – about A$2,000 to A$2,500 – but costs are coming down.
Once a mutation has been identified in a family member, other members can be tested and this is much cheaper.
In Australia, the test is offered for free in familial cancer centres where a person meets suitable criteria for testing.
How many people are affected?