What Is My Risk of Developing Breast Cancer?

All women in the US, regardless of family history, have a minimum 1:8 or 12.5% risk of developing breast cancer in their lifetime.

Of those that do, 5-10% are considered to be heritable, or strongly related to inheriting a known harmful genetic mutation in a breast cancer predisposition gene. 15-20% are considered to be familial, or family history shows multiple affected family members in multiple generations, but genetic testing is negative for a known breast cancer associated genetic mutation. Meanwhile, 75-80% are considered sporadic, or most likely due to a combination of many factors – non-modifiable and modifiable.

If you have many of the non-modifiable and modifiable risk factors discussed in my previous blog post, your risk is likely more than 12.5%.

Know Your Family History of Breast Cancer

It is very important to know your family history as it strongly informs your personal risk of developing breast cancer.

You should be proactive in obtaining this information while family members are still alive. The information you should try to learn includes:

• Who in your family has had cancer?
• How old were they when they were diagnosed?
• Did they die from the cancer and if so, at what age?
• What kind of cancer(s) did they have?
• If they had breast cancer, was it hormone sensitive (estrogen receptor positive or negative, progesterone receptor positive or negative)?
• Was it HER2 positive or negative?
• How was it treated?

Risk Assessment for Breast Cancer

If you have a strong family history of breast or ovarian cancer in first (children, parents, siblings) or second (grandparents, aunts, uncles) degree relatives, or in successive generations, you can undergo Genetic Cancer Risk Assessment in a High Risk Breast Cancer Clinic.

There are a number of risk assessment models that are applied using your personal and family medical history to obtain your personal risk. If your lifetime risk for developing breast cancer is over 20% or 1:5, you would be eligible for a more intensive screening protocol which includes clinical exams, mammograms, and MRIs.

If your family history is suggestive of a possible inherited genetic cancer syndrome, you could have genetic testing. If you are found to have a genetic mutation associated with the development of breast cancer, in addition to aggressive screening, you may be able to consider risk reduction hormone blocking therapy as well as possible risk reduction surgery.

Being proactive and understanding your risk will allow you to take positive steps toward reducing your risk, and your stress, and hopefully, if you do go on to develop breast cancer, detecting it at a very early stage when it is most treatable.