Genetics Northern California

Breast and Ovarian Cancer

Most breast and ovarian cancers are due to common risk factors, like age, lifestyle, and exposures. However about 5% to 10% of breast cancers and 20% of ovarian cancers are due to inherited cancer risk.

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 is 1 in 8 (about 12%). The chance of developing ovarian cancer is 1 in 70 (1.4%). Breast cancer in men is rare, about 1 in 1000.

What is known about cancer risk genes for breast and ovarian cancer?
The first two cancer risk genes were discovered in 1994 and 1995 and are called BRCA1 and BRCA2. Both of these genes help protect the body from breast and ovarian cancer. When there is a harmful genetic change (mutation) in either one, it raises the chance to develop breast cancer and ovarian cancer. BRCA1 and BRCA2 account for many cases of hereditary breast and ovarian cancer, but there are many other cancer risk genes that can increase the risk for these cancers. Anyone can have harmful changes in a cancer risk gene, regardless of their gender or ancestry.

How do you know if someone has a harmful change in a cancer risk gene? 
The cancer history in a family can suggest the possibility of inherited cancer risk. Genetic testing can be done to look for harmful changes in many cancer risk genes.

These fact sheets give more information:

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

       1.      Several family members with breast cancer
2.      Breast cancer diagnosed at early ages
3.      Ovarian cancer in the family
4.      A family member with more than one cancer (Ex: cancer in both breasts; or breast and ovarian cancer) 
5.      A male family member with breast cancer

How can I learn about my genetic risk for breast and ovarian cancer?
You can learn about your genetic risk by talking with a genetic counselor. Appointments are made through your local Kaiser Permanente Genetics Department. You can ask your healthcare provider for a referral or call the Genetics department yourself.

What should I expect when I call the Genetics department?
You may be scheduled for an appointment to review the family history and talk about genetic testing. Before the visit, you are encouraged to watch an online video program called “Inherited Cancer Risks”.  The video program covers general information about cancer risk genes and may help you decide if you want a Genetics appointment. It can also help you prepare for an appointment.

How do I prepare for a genetic counseling appointment?
Before your genetic counseling appointment, gather as much medical information as you can about your family. It is helpful to know the type of cancer and the age at diagnosis for anyone who has had cancer. It is also helpful to get a copy of genetic test results from anyone who has had testing.

  • 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 show 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 cancer is estimated. The potential impact of genetic risk for you and your family is addressed. Genetic testing is also talked about during visit, but may not be useful for all families.

Last reviewed: January 22, 2021
Reviewed by: Kimberly Barr, MS, LCGC