Genetics Northern California

Breast and Ovarian Cancer

There is a lot written about families with an inherited risk for cancer, but only about 5-10% of breast cancer and 10-15% of ovarian cancer is due to an inherited risk. Most breast and ovarian cancer is due to non-inherited genetic errors in cells of the body. These errors happen randomly over a lifetime. 

What is the chance of developing breast or ovarian cancer?
If you are female and live to age 80, your chance of developing breast cancer at some point in your life is one in eight or about 12%. The chance for developing ovarian cancer is one in 70 or 1.4%. Breast cancer in men is rare, about one in 1000.

What is known about the genes that increase the risk for breast/ovarian cancer?
In 1994 and 1995, two genes were identified which are known as BRCA1 and BRCA2. Both of these genes help protect against the development of breast and ovarian cancer. When there is a mutation (genetic change) in either one of these genes, they may no longer offer protection against these specific cancers. BRCA1 and BRCA2 account for most of the inherited risk for breast and ovarian cancer. More recently, we have found other genes that can increase the risk for breast and ovarian cancer in some families.

How do you know if someone has a mutation in a cancer risk gene? We start to identify those at a higher genetic risk by reviewing the family's cancer history. We ask about the ages of family members when they were diagnosed with cancer, the particular types of cancer, and the relationship between family members who have cancer. We look at both sides of the family (your mother's side and your father's side). Cancer risk genes can be carried by men as well as women. For some individuals or families, DNA testing is available to identify mutations.

These handouts give more information about cancer genetics:

Families with inherited breast cancer risk are more likely to have the following:

  1. Multiple family members with breast cancer, usually in more than one generation 
  2. Breast cancer diagnosed at early ages
  3. Both breast and ovarian cancer in the family
  4. A family member with more than one cancer (for example: cancer in both breasts; or breast and ovarian cancer in the same person) 
  5. A male family member with breast cancer

How can I learn about my personal genetic risk for breast and ovarian cancer?
Evaluation and counseling about your personal and family history of cancer is available through your local Kaiser Permanente Genetics Department. You may be referred by your healthcare provider, or you may call the Genetics department yourself.

What should I expect if I call the Genetics department to ask about my breast and ovarian cancer risk?
You may be offered an informational class to start the process of genetic counseling. Our Breast and Ovarian Cancer class is available online or in-person. The class provides general information about the cancer risk genes, family history, genetic testing, and cancer risk management. Information from the class can help you decide whether or not you want to learn more about your personal risk for cancer. It may also better prepare you for a genetic counseling visit to discuss your family history and the possibility of genetic testing.

How do I prepare for a genetic counseling appointment?
Before contacting your local Kaiser Permanente Genetics Department, gather as much medical information as you can about your family. It is especially helpful to know the type of cancer and the age at diagnosis for anyone who has had cancer in your family.

  • Use our Family History Form to help keep track of the information you learn. 
  • You may be asked to get medical records or death certificates on some of your family members. This can help determine whether or not genetic testing is useful for your family

What happens during a genetic counseling visit?

A genetic counseling visit might be scheduled as a phone appointment, a video visit, or an in-person visit. You are asked about all your relatives, including those with and without cancer. Your genetic risk for breast and ovarian cancer is determined. The potential impact of genetic risk on you and your family will also be addressed as part of genetic counseling. Genetic testing is routinely discussed as part of the genetic counseling visit, but may not be appropriate for all families. 

Online breast/ovarian cancer support sites for individuals with inherited cancer risk:

  • FORCE: Facing Our Risk of Cancer Empowered -
    National non-profit dedicated to improving the lives of individuals and families affected by hereditary breast and ovarian cancer.
  • Bright Pink -
    National non-profit focused on prevention and early detection of breast and ovarian cancer in young women while providing support for high-risk individuals. 

Related handouts 

Last reviewed: November 30, 2017

Last revised: November 30, 2017
Reviewed by: Kaiser Permanente Genetics