If you test positive for a BRCA mutation what should you do?
Studies show that a woman with a harmful (pathogenic) BRCA mutation has a lifetime risk of up to 80% of developing breast cancer and up to 40% of developing ovarian cancer. A man has lifetime risk of up to 5% of developing breast cancer and up to 40% of developing prostate cancer.
All individuals who test positive should discuss their personal and family history with a qualified healthcare provider or genetic counsellor so that appropriate screening and treatment options, and options for prophylactic surgeries can be planned.
If you test positive does that mean you have cancer?
A positive test result means that an individual carries a pathogenic mutation which increases the risk of breast and ovarian cancer in woman, and breast and prostate cancer in men. However a positive result does not mean that you have cancer or that you will definitely develop cancer. In fact some people who carry a pathogenic mutation may never develop cancer.
If you test positive should you be tested for other forms of cancer?
If your result is positive you should discuss this with your healthcare provider and a genetic counsellor as interpretation depends on your personal and family history. Further evaluation and testing may be recommended for you and first degree relatives.
What does a negative test mean?
A negative test can sometimes be more difficult to understand than a positive test.
If you are the first, second or third degree relative of a person known to carry a pathogenic mutation, a negative test means that you do not carry the mutation. You have the same risk of breast and ovarian cancer as the general population. Your children cannot inherit this particular mutation from you.
A negative result is less clear if you or any close blood relative has a personal or family history that suggests a BRCA mutation. Possible causes for this include:
- a false-negative test for a known mutation which, although rare, can occur
- an as yet unknown pathogenic BRCA mutation
- a pathogenic mutation in another gene
If you are considering testing for a BRCA mutation you may want to discuss these potential uncertainties with your healthcare provider or a genetic counsellor.
Can your test result be inconclusive?
Yes. This result is called a variant of uncertain significance [VUS]. This is a genetic mutation whose effect on cancer risk is not yet well established due to limited and/or conflicting evidence in the medical literature. As scientists learn more a VUS may be reclassified into a benign or pathogenic which may impact you and your family in the future. If you are considering testing for a BRCA mutation you should consider the effect of a VUS on you and your family. You may want to discuss this potential uncertainty with your healthcare provider or a genetic counsellor.
