BRCA testing and familial ovarian cancer
The two genes involved in familial breast cancer, BRCA1 and BRCA2, are also involved in familial ovarian cancer and many families are looking for information on the possibility of genetic testing for ovarian cancer. Around 10 per cent of ovarian cancer cases are thought to be genetic.
Can I have a genetic test to see if I will develop ovarian cancer?
Most cancer genetic cancer centres offer testing to families with at least two people affected with ovarian or breast cancer from the mother’s or father’s side.
Genetic testing is a complex process. The two genes involved in ovarian cancer are BRCA1 and BRCA2, which are very long genes. Faults can occur at any points along the length and different families have different faults. The first step is to take a blood sample from a family member with ovarian or breast cancer and identify the fault from that sample. Genetic testing can then be offered to other family members if they want to know whether they have inherited the fault.
Of course, you do not have to take up the offer of a genetic test. Some people may simply not wish to know.
What are the options if I am found to have a faulty gene?
If you have the faulty gene you may be offered surgery to remove the ovaries and fallopian tubes to reduce your risk of developing ovarian cancer. You may also be given information about signs and symptoms of ovarian cancer to look out for and encouraged to report these to your GP along with your family history and genetic information.
If you have a faulty BRCA1 or BRCA2 gene you are also at increased risk of breast cancer, and again the options are similar: You may be offered screening, a regular mammography to pick up any early breast cancer. You may also be offered surgery: a bilateral mastectomy to remove both breasts to prevent the development of breast cancer.
It is likely that a third option of taking different drugs in research studies to try and prevent the development of these cancers will become available soon. One study, the International Breast Cancer Intervention Study (IBIS) offers a trial of Tamoxifen or a dummy tablet to those with a family history of breast cancer. There are no drug studies available for women with a family history of ovarian cancer, or for women who have had a genetic test which proves they carry the faulty BRCA1 or BRCA2 genes.
What if I have not inherited a faulty gene?
If you do not have the faulty gene which runs in your family, then your chance of developing ovarian or breast cancer is no higher than anyone else your age in the population, and therefore extra screening will be stopped. You will still be encouraged to join the National Breast Screening Programme when you are 50.
My mother has ovarian cancer, should I be screened?
If your mother is the only person in the close family who has developed ovarian cancer or breast cancer then your risk of ovarian cancer is only slightly increased. There is currently no screening available on the NHS.
I have ovarian cancer. What’s the risk for my daughter?
If you have not inherited the faulty gene which runs in your family, extra screening is not necessary. The risk to women in this group is slightly, but not greatly, increased. The risk increases if more family members have developed ovarian or breast cancer.
The current view is that the value of ovarian cancer screening for your daughter is uncertain. Two large screening trials are due to report their final results by 2019. If these show that screening for ovarian cancer can save womens’ lives then a national screening programme could be introduced.
Last review April 2016
Date of next review April 2018