A positive test means that your chance of developing certain cancers will be higher than someone who does not have a mutation in these genes.
Your risks of different cancers will depend on the specific mutation you have inherited and should be explained to you, in detail, by your genetics team. You will also be given a letter that gives you information about your mutation and the risks associated with it.
Here are some general risks to give you a basic idea of the implications of having a genetic mutation.
A mutation in your BRCA1 or BRCA2 gene will mean you are at an increased lifetime risk of cancer, as shown below. Remember, this is an increased chance of cancer, not a guarantee you will get cancer in your lifetime.
The table below shows estimated cancer risk by age 70.
|Type of cancer||General population||BRCA1||BRCA2|
|Breast cancer in women||11%||60-85%||45-60%|
|Breast cancer in men||0.1%||Up to 3%||Up to 12%|
|Prostate cancer||12%||Unknown – likely similar to normal population||20-25 %|
(There is research suggesting an increased risk of pancreatic cancer for people who have these mutations, but research is ongoing into how much they increase risk.)
Note: men can get breast cancer too!
It’s important to understand that the figures above are risks for your whole life. Another way of looking at your risk is to look at what age the risk increases:
Risks of breast and ovarian cancer for BRCA1 and BRCA2 by age
Graphs adapted from Antoniou et al. AJHG 2003
In both BRCA1 and BRCA2, the graphs show no significant increased risk of ovarian cancer until age 45. If you have a BRCA1 gene mutation, risk increases at age 45-49 and again at age 55-59. Risk increases later if you have a BRCA2 gene mutation. You should also consider the age your relatives developed ovarian or breast cancer. You should discuss these risk factors with your genetic counsellor.
A mutation in one of the genes linked to Lynch Syndrome will mean you are at an increased lifetime risk of cancer. Remember, this is an increased chance of cancer, not a guarantee you will get cancer in your lifetime. The table below shows estimated risk by age 70.
|General population||Lynch syndrome|
|Colorectal cancer||5.50%||Up to 80%|
If you have any questions please contact Jo@ovarian.org.uk