Breast Cancer - Risk Assessment
by Jennifer Park, MD, FACOG
Who is at increased risk for breast cancer? What can you do to lower your risk?
There have been several new advances in screening for breast cancer. With these new techniques, knowing your own risk for breast cancer risk is now very important. This article reviews the key factors that you need to know about your medical history to help your doctors better determine your risk for breast cancer and to be able to guide what testing should be offered to you.
Family history is one of the most important pieces of information that you can give your doctor. There is a hereditary breast and ovarian cancer syndrome for which genetic testing is available. Two gene mutations are tested for, called BRCA1 and BRCA2. About 3-5% of all cases of breast cancer are due to mutations in these genes. In the general population, about 1/300 to 1/800 individuals carry one of these mutations.
You may be a candidate for testing for these gene mutations if you have any of the following “red flags“ in either a first or second degree relative (which includes a parent, a sibling, a child of yours, or a biological aunt, uncle, niece or nephew): a person affected by both breast cancer and ovarian cancer, a person affected by breast cancer at age 40 or younger or any male family member with breast cancer. Testing may also be warranted if there are multiple family members affected with breast cancer of any age. Certain ethnicities are also considered at increased risk for BRCA1 and BRCA2, specifically those who are of Ashkenazi Jewish, French Canadian (Cajun) or Icelandic ancestry.
The ideal person to be tested for BRCA1 or BRCA 2 is the “affected individual”, meaning the person in the family who has the early onset breast cancer or ovarian cancer. This allows testing of family members to be more specific and less costly. If that individual is not available for testing, a patient can still get tested.
Since hereditary breast cancer syndromes only account for a small percentage of breast cancers, there are other tools used to measure one’s risk. These tools (computer software programs) take into account the age at which you first started having periods, the age at which you had a first live birth, any previous breast biopsies, and your current age. This information is then used to determine a percentage lifetime risk for breast cancer (the percent chance of having breast cancer at any point in one’s lifetime).
A screening mammogram is the standard test used for early detection of breast cancer. A new type of breast cancer screening ultrasound called SonoCine (not yet FDA approved) is also available in some locations. This test can sometimes identify a cancer missed by a mammogram, particularly in women with “dense” breasts.
Breast MRI is the newest recommendation by the American Cancer Society for women at very high risk for breast cancer, meaning greater than a 20-25% lifetime risk. Breast MRI can also identify a difficult to diagnose pre-cancerous condition called DCIS. Screening MRI is not recommended for women with less than 15 percent lifetime risk.
Other factors that may increase your risk for breast cancer include: increasing age, delayed childbearing or having no children, late onset menopause, postmenopausal hormone usage, obesity, and alcohol usage. Despite widespread concern, there is no proven increased risk for breast cancer among oral contraceptive users or caffeine drinkers. There is an increased risk for postmenopausal women on combination estrogen and progesterone but not for those on estrogen alone.
There are some lifestyle changes that can decrease your risk for breast cancer. These include limiting alcohol consumption, maintaining a healthy adult weight and regular physical exercise. Other factors that are associated with a lower risk for breast cancer include having children at a younger age and breast feeding for greater than six months. Postmenopausal women can decrease their risk by shortening the duration of combination hormone therapy. For those considered at higher risk, medication can be prescribed to decrease their risk. Monthly self breast exams and routine clinical exams by your physician are also important.
Many advances have been made in breast cancer screening and prevention. The first step is to know your family history. Know the ages at which each member was affected by cancer and discuss this with your physician. He or she will determine if either genetic testing or advanced screening MRI is needed. If you have any lifestyle issues associated with a higher risk of breast cancer, try to change them to lower your risk, and keep in mind that early detection of breast cancer is the key to surviving!