Genetic Testing and Breast Cancer: Forewarned is Forearmed
I recently had an opportunity to tour the Myriad Genetics Laboratories Utah headquarters with a group of women’s imaging specialists. Myriad wanted to familiarize us with the genetic testing process and discuss how we can incorporate genetic testing into our practices. Women with the BRCA1 and BRCA2 gene mutation have a higher risk of developing breast or ovarian cancer; approximately 5 – 10 percent of breast cancer cases are caused by genetic mutation. Genetic testing at imaging centers makes sense. We develop individual cancer risk profiles for our patients and a genetic mutation would be a key factor. We already document family histories so the genetic component can be added seamlessly.
So what are the BACA genes and who should be tested to see if they carry BRCA gene mutations? The job of our BRCA genes is to keep breast cells functioning smoothly. If there is a mutation that is passed down through the generations, the BRCA genes stop doing their job and cancer can result.
Family history is the key component in determining who should be tested. Consider genetic testing if your risk factors match this profile. You have:
Blood relatives who were diagnosed with breast cancer under the age of 50;
A family member with both breast and ovarian cancer;
Family members with cancer in both breasts;
Eastern European (Ashkenazi) Jewish ancestry;
A male family member with breast cancer.
If you have a strong family history, it is important to know if your relatives with breast cancer have been tested. That will provide the most information to compare with you and others in your family. If someone in your family has already been tested and found to have the BRACA mutation and your test is negative, then it is considered a “true negative.” You are at the same risk as the general population. If you have a strong family history of breast cancer but no one has tested positive and you do not either, you should still consider yourself to be at higher risk of developing breast cancer. Genetic testing is still in its infancy. We know that other genetic abnormalities are implicated in causing cancer but we don’t yet know what they are or how to test for them.
Women who have BRCA gene mutations – and those with negative results but a strong family history - should make an action plan with their doctors. Forewarned is forearmed - you have to plan now while you’re in good health. Choose one of these options:
Surgery - You can take Angelina Jolie’s path to breast cancer prevention; a prophylactic double mastectomy reduces your risk to almost 0.
Surveillance - Your radiologist can develop an enhanced screening program, utilizing several modalities which all have different methods of detecting tumors.
Chemoprevention – You can take prophylactic medication such as Tomoxifen.
Breast cancer has been associated with many risk factors including breast density, benign breast disease, late menopause, early menarche, post- Menopausal obesity and Hormone Replacement Therapy. But genetic mutations are the risk factor most strongly associated with developing breast cancer; a ten-fold increase.