Why Is It Important to Know My Lifetime Breast Cancer Risk?

Understanding your risk of developing breast cancer will help you make well-informed decisions about your health.  You may choose to minimize or eliminate risk factors that you can control; other risk factors may be beyond your control. Women with the average risk for breast cancer are advised to get an annual mammogram, beginning at age 40.  If you are a woman with an increased risk you may want to discuss additional steps to detect breast cancer as well as preventive treatments with your health care provider. Understanding your own personal risk and what that means will help you to weigh the risks and benefits of screening and prevention measures that your physician may suggest and to make intelligent choices about your care.

Understanding Breast Cancer Risk

Breast cancer risk is expressed in two different ways. Absolute risk is a woman’s chance of developing breast cancer within a certain period of time. Relative risk compares the absolute risks of groups with and without a certain risk factor.  For example, the absolute lifetime risk of developing breast cancer for women in general is 12.3%, but the absolute risk of any given woman will vary depending on risk factors, such as genetic predisposition, personal medical history, or alcohol intake.  Relative risk helps women and their care providers understand the impact of individual risk factors that influence each woman’s health. If a woman has a high risk of developing breast cancer, her doctor may recommend additional methods of prevention and early detection.

At Iowa Radiology, we gather information from our patients to evaluate their breast cancer risk using the Tyrer-Cuzick model, a tool designed to calculate a woman’s lifetime risk of breast cancer development. The Tyrer-Cuzick model takes the following factors into account:

• Age
• Body mass index (BMI)
• Family history
• Ages at menarche, first live birth, and menopause
• Hormone replacement therapy (HRT) use

If the Tyrer-Cuzick model indicates that a woman has a 20% or greater lifetime breast cancer risk, we include that information in our report to her health care provider to inform decision making about steps to take to best to manage her health.

Breast MRI 

The American Cancer Society (ACS) and the American College of Radiology (ACR) recommend additional screening for women with an absolute lifetime risk of breast cancer of around 20% or greater, based on certain factors.  The organization suggests that women who have BRCA1 or BRCA2 gene mutations or first-degree relatives with one of these mutations, have certain other specific genetic predispositions, or have undergone radiation therapy to the chest between the ages of 10 and 30 obtain breast MRI screenings in addition to their annual mammograms. Although the ACS advises that for women in this category, the use of imaging for breast cancer screening should typically begin at age 30, when exactly to begin is an individual decision to be made by each woman in consultation with her physician.

Genetic Testing

Some women who are at greater risk for breast cancer based on family history may be referred to a genetics professional for a consultation about genetic testing.  If the genetics professional believes there is a reasonable suspicion that a mutation of the BRCA gene is present, then he or she may recommend genetic testing. It is important for any woman considering genetic testing to receive thorough information from a genetics professional so she understands the benefits, costs, and limitations of these tests.

Chemoprevention

There are also drugs available that can reduce a woman’s risk of developing breast cancer.  Use of drugs in this way is called chemoprevention.  These drugs can have serious side effects, so any woman considering taking them must consult with her health care professional to ensure that she is an appropriate candidate for chemoprevention and to gain a full of understanding of the risks and potential benefits.

Prophylactic Mastectomy

If a woman has a very high lifetime breast cancer risk, her physician may suggest a prophylactic (preventive) mastectomy. Removing both breasts before cancer is diagnosed can reduce the risk of developing breast cancer by up to 97%. Some women who develop cancer in one breast choose to have the other removed prophylactically. Because even the most careful of surgeons cannot remove every single breast cell, and any cells left behind may become cancerous, even mastectomy is not a 100% guarantee that breast cancer will not develop.  The American Cancer Society cautions that prophylactic mastectomy should only be used when warranted by strong indications of very high risk and advises all women to obtain at least two professional opinions before going forward with this option.

Medical science offers a variety of ways to screen for, prevent, diagnose, and treat breast cancer.  In order to find the best course of action for you, it is important to understand your lifetime breast cancer risk and what is influencing it. Some factors, such as obesity or alcohol intake, can be controlled, while others, such as family history and genetic predisposition, cannot.  Understanding your risk factors and how they influence your overall risk will help you and your doctor to make the best choices for your health care. Subscribe to our blog today for ongoing health care updates.