What is Hereditary Breast and Ovarian Cancer Syndrome?
Hereditary Breast and Ovarian Cancer Syndrome (HBOC) is a genetic condition that increases the risk of developing breast, ovarian cancer and other cancers. It can be passed from parent to child, across generations, and affect multiple family members.
What Causes HBOC?
HBOC is usually caused by mutations (changes) in the BRCA1 or BRCA2 genes. These genes normally help prevent cancer, but mutations may weaken their ability to protect against breast and ovarian cancer. These mutations are typically inherited from a parent.
Who Can Be Affected by HBOC?
People with a personal or family history of breast, ovarian, and other cancers have an increased risk of HBOC. This condition affects both men and women, whether or not they've had cancer.
- About 1 in 500 people have a BRCA1 mutation
- About 1 out of 225 have a BRCA2 mutation
- In Washington, an estimated 52,000 people have HBOC
Not everyone with HBOC will develop cancer. However, HBOC accounts for about:
- 5-10% of breast cancers
- 10-15% of ovarian cancers
What Can You Do?
If you have HBOC, you can take steps to lower your risk and find early:
- Get regular cancer screenings. Talk to your provider about starting screenings earlier than the recommended age.
- Ask about preventative treatments. Find out about which treatments may be available for you.
- Get a complete diagnosis. Make sure to have a full diagnosis that includes genetic testing. This information helps tailor treatments for you.
- Share information with family members. Let your family members know through a process called cascade screening. First- and second-degree relatives may also carry this mutation and can take steps to reduce their risk of HBOC-related cancers.
Find Genetic Services
- Locate the nearest genetic provider.
- Learn about health insurance coverage and reimbursement for genetic services, such as genetic counseling or testing on the Facing Hereditary Cancer website.
Resources For Providers
Breast Cancer Risk Assessment Tools
- Tyrer Cuzick Model
Estimates lifetime breast cancer risk based on personal and family history. The Tyrer-Cuzick model is not intended to assess the risk of women who have already been diagnosed with breast cancer. - CanRisk (BOADICEA v6 model)
Assesses breast and ovarian cancer risks based on personal risk factors, cancer family history, genetic testing for high- and moderate-risk genes, polygenic scores and mammographic density. - Breast and Ovarian Cancer Genetics Referral Screening Tool
Free online tool for assessing hereditary breast and ovarian cancer risk. - Cancer Genetic Clinic Locations
- Cancer screening in Washington
General information about cancer screening and health insurance coverage. - Cancer Family History Questionnaire (PDF)
Forms to assist patients with family history information and assess risk for breast cancer. - Family Health History
HBOC Resources and Guidelines for Providers
- HBOC resource for Providers
National Library of Medicine offers information about BRCA1- and BRCA2-associated hereditary breast and ovarian cancer. - Hereditary Cancer Management Guidelines
The Jackson Laboratory offers guidance on managing individuals at increased and high risk of cancer. - National Comprehensive Cancer Network Guidelines
Breast, ovarian, pancreatic, and prostate cancer risk Version 2.2025 (Free to sign up, need login to access) - Hereditary Breast and Ovarian Cancer information
Information about HBOC from the CDC.
Resources for Patients
Genetic Risk and Cancer Screening
- Breast and Ovarian Cancer Genetics Referral Screening Tool
Free online risk assessment tool. - Bring Your Brave Campaign (CDC)
Information for young women at risk. - Cancer screening in Washington
HBOC Support and Education
- Facing Hereditary Cancer Empowered
- BRCA1 and BRCA2 information and resources
- Hereditary Breast and Ovarian Cancer information (Centers for Disease Control and Prevention)
Questions?
Please contact the Screening and Genetics Unit for questions or information about Hereditary Breast and Ovarian Cancer syndrome.