The short answer is yes, you should definitely get tested.
For many years, we thought cancer was just something that happened to people either by chance or because of lifestyle habits such as smoking. But in the last 20 years we’ve discovered that there are genetic predispositions to cancer—specific changes in certain genes (what used to be called mutations but are now called variants) that can increase a person’s risk for certain cancers. BRCA1 and BRCA2 are the most well-known of these genes, but there are others, as well. In addition to increasing your risk of breast cancer, variants in BRCA1 and BRCA2 may also be associated with an increased risk for ovarian cancer.
If your mother has a variant in BRCA1 associated with an increased risk for cancer, it means you have a 50 percent chance of having inherited that same variant. If you are tested and found to have the variant, that knowledge gives you the opportunity to take control of your life and take action to minimize your risk. It’s completely understandable to be nervous about having this test, but really it’s all about empowerment. Genetics helps patients and their family members make the best decisions for their own health. Knowledge is power!
Some women who test positive for a cancer-predisposing variant in BRCA1 or BRCA2 decide to have a bilateral prophylactic mastectomy, which means both breasts are removed as a preventive measure against breast cancer. The surgery has been shown to reduce the risk of breast cancer by 90 to 95 percent. Some women may also opt, once they know they are done having children, to have both ovaries removed.
But these are not the only options available. Early detection is also at the core of what we do, and that means increased surveillance. Often, what that means is that women who test positive for cancer-predisposing variants in BRCA1 and BRCA2 not only follow the general population guidelines for breast cancer screening, but in addition, they begin getting mammograms and MRIs 10 years earlier than the youngest breast cancer case in their family.
When it comes to your daughters, the answer is no, we don’t recommend having them tested at these young ages. As far as we know, the cancers that are associated with BRCA1 and BRCA2 variants occur in adults. When your daughters reach the age of 18, they can make their own decisions about whether or not to get tested. Importantly, sons can inherit cancer-predisposing variants too, which may increase their personal risk of cancer, as well as their children’s risk of cancer. So, if you have any sons, they should also consider genetic testing when they turn 18.
Other candidates for genetic testing include people who:
- Have had a cancer diagnosed at an early age, such as breast cancer before the age of 50, or have a close family member who was diagnosed with cancer at an early age
- Have two or more close family members diagnosed with the same type of cancer or related cancers, such as breast and ovarian cancer, or colon and uterine cancer
- Have had more than one cancer, or have a close family member with more than one cancer
- Have been diagnosed with certain types of cancer, such as breast cancer, AND who are from certain ethnic groups, such as Ashkenazi Jews, in which inherited cancers are more common than in other ethnic groups
- Have been diagnosed with certain rare cancers, such as medullary thyroid cancer
Before getting tested, though, I recommend having a thorough evaluation by a genetic counselor and a clinical cancer geneticist. The evaluation involves a personal medical history as well as an extremely detailed family history, ideally going back at least three generations. Together, you can think through the risks and benefits of genetic testing and decide whether it is the right decision for you and your family.