The original version of the content below appears in A Guide to Caring For Yourself inside A Calendar to Live By 2021.
Written in collaboration with Myriad Genetics.
Only about 12 to 14 percent of all breast cancer is caused by an inherited genetic mutation (from either mother or father), and only 5 to 10 percent of those diagnoses are associated with a genetic mutation that has been identified. But this is why knowing your family medical history is so important! When it comes to breast cancer risk, the most important inherited gene changes that significantly increase risk of breast and/or ovarian cancer are on the BRCA1 and BRCA2 genes, but there are other known inherited genetic changes that can also increase risk.
Thanks to advances in and the increased availability of genetic testing, more women diagnosed with breast cancer or those who have a family history of various cancers can get information on their hereditary cancer risk to help make important decisions. For those who already have breast cancer, genetic testing can help doctors make treatment decisions, such as the best immediate surgical options (e.g., mastectomy vs. lumpectomy).
Breast cancer patients with a BRCA mutation may have up to a 20 percent risk for a second primary cancer within five years and a 12.7 percent risk of ovarian cancer within ten years of initial diagnosis. So, for those with breast cancer or a family history of breast or ovarian cancer, genetic testing can also help determine the best future risk management plan (e.g., increased surveillance vs. risk-reducing surgery). This information can help inform non-surgical treatment options too – for example, it can help a doctor decide whether to use targeted therapies such as PARP inhibitors to treat certain metastatic breast cancers in those with a BRCA gene mutation.
The decision to do genetic testing is a personal one, so we recommend discussing with your doctor whether genetic testing is right for you. You can also take a hereditary cancer quiz to find out if you meet clinical criteria for testing at hereditarycancerquiz.com.