Breast cancer is very common and one in eight women will develop breast cancer over their lifetime. As a breast oncologist who specializes in prevention I often get asked “what is my risk?” There are several risk factors for breast cancer: starting menses early, late menopause, never having children, not breast feeding, personal history of prior breast biopsies, obesity, alcohol (use of more than 3 drinks/week), lack of exercise, radiation treatment to the chest and family history of breast cancer.
There are risk models that will calculate your risk of breast cancer based on some of these factors. The most common models are the Gail and Tyrer Cuzick models. If the 5 year risk is >1.67%, then medications such as Tamoxifen or Raloxifene can be taken for five years and will reduce breast cancer risk by at least 50%. These medications are usually very well tolerated and the most common side effects are mild hot flashes and vaginal dryness. If the lifetime risk is >20-25%, then additional screening such as breast MRI can be added to annual mammography, which can detect cancer at earlier stages. This is why knowing your risk is so important. If you have any of the risk factors listed above, ask your doctor to run a breast cancer risk model to calculate your risk for breast cancer and see if you qualify for medications to prevent cancer or annual screening breast MRIs.
Sometimes breast cancer can run in families, and if it is due to a mutated gene, it is knows as a hereditary breast cancer syndrome. Genetic testing can be offered to families when a hereditary breast cancer syndrome is suspected. Insurance companies will often cover the cost of this testing, and medical coverage cannot be denied due to the results of genetic testing. Genetic testing is recommended if there is anyone with breast cancer diagnosed at age 45 or younger, triple negative diagnosed at the age of 60 or younger, three women with breast cancer on the same side of the family, two women with breast cancer on the same side of the family if one was diagnosed before age 50, all cases of ovarian cancer (breast and ovarian cancer are often seen in these syndromes), and some combinations with other cancer such as pancreatic cancer, prostate cancer and melanoma or many individuals with cancer in the family. If this describes your family, you should consider meeting with a genetic counselor to see if genetic testing for your family is indicated. It is always best to test the person with cancer in the family if they are still living. Genetic testing when indicated is very important because hereditary cancer syndromes are associated with very high rates of cancer at younger ages. For example the BRCA1 gene has a lifetime risk of breast cancer as high as 87% (half develop breast cancer before the age of 50) and lifetime risk of ovarian cancer up to 44%. If someone is found to have a BRCA1 gene, we would follow that individual closely in a breast center and consider prophylactic mastectomies versus more careful monitoring with annual mammogram, annual breast MRI and medications such as tamoxifen to reduce breast cancer risk. If you are worried about your risk of breast cancer ask for a referral to a breast center for a comprehensive breast cancer risk assessment!
Dr. Julie Nangia
Director of the Breast Cancer Prevention & High Risk Clinics at Baylor College of Medicine
Advisory Board Member Indian American Cancer Network