Genetic Testing for Breast and Ovarian Cancer
Hereditary cancers occur because of a change (mutation) in certain genes that normally protect the body from developing cancer. This change increases a person’s risk for one or more types of cancer and can be passed from generation to generation.
For some genes, the risk is attributed to more than one type of cancer. The main hereditary breast cancer syndromes are also associated with an increased risk of ovarian cancer.
Hereditary breast and ovarian cancer risk can be passed down from either parent to their daughters or sons.
Signs of hereditary breast-ovarian cancer syndrome
Signs of hereditary breast-ovarian cancer syndrome may include but are not limited to:
- Breast cancer at age 45 or younger
- Breast cancer in both breasts at any age
- Both breast and ovarian cancer in the same woman
- Two or more people within a family with ovarian cancer and/or breast cancer, especially if the breast cancer was diagnosed at or before age 50
- At least one family member with breast cancer and one with ovarian cancer
- Breast cancer in men
- Ashkenazi Jewish heritage and ovarian cancer at any age or breast cancer before age 60
The two genes most commonly associated with hereditary breast and ovarian cancer are BRCA1 and BRCA2.
People who have any of the risk factors for hereditary breast and ovarian cancer may wish to learn if they carry a mutation in BRCA1 or BRCA2. This testing is performed with a blood or saliva sample.
A positive genetic test indicates that a person has an increased risk for developing cancer. However, a positive result does not mean a person definitely will get cancer.
A negative test result does not mean a person will not get cancer sometime in his or her life.
These genetic mutations are very common in certain populations. For instance, experts estimate one in every 40 people of Eastern European (Ashkenazi) Jewish descent carries one of three particular BRCA1 or BRCA2 mutations.
Experts believe there are other genes related to cancer risk, but tests are not yet available to detect these gene changes. Therefore, a negative genetic test cannot totally rule out a hereditary cancer syndrome in a family.
Genetic testing results may affect treatment and follow-up options for women who have had breast or ovarian cancer.
For these reasons, it is important to speak with a specialist in cancer genetics if you are concerned that cancer may run in your family.
How can I find out if I am at risk for hereditary cancer?
A cancer genetic counselor, geneticist, or risk assessment counselor can help you understand hereditary cancer more clearly. This person will:
- Review your family history of cancer
- Assess and explain your risk for hereditary cancer
- Describe the benefits and drawbacks of genetic testing and discuss whether you are a candidate for the test
- Interpret genetic test results and explain what they mean for you and your family
Receiving genetic counseling does not mean that you are required to have a genetic test.
If you do not test positive for a genetic mutation, there are options available for decreasing your cancer risk. These options will be described to you during your genetic counseling session.