Hereditary Breast and Ovarian Cancer Syndrome: A Guide for Patients and Their Families

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Hereditary Breast and Ovarian Cancer syndrome (HBOC) is a genetic condition that makes it more likely that a person will get breast, ovarian, and other cancers. HBOC is hereditary, meaning that it is caused by a mutation (genetic change) that can be passed down in families. A genetic test can help determine if your personal or family history of cancer was caused by HBOC. If you are found to have HBOC, there are interventions that can help prevent cancer or detect it early. To learn whether you are more likely to have HBOC, collect your personal and family history of cancer and share this information with your healthcare provider. You can use the Know:BRCA tool to collect this information and assess your risk of having a BRCA mutation in preparation for your visit to your doctor.


First, talk with your health care provider. You can also find more information on HBOC at:

Centers for Disease Control and Prevention

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HBOC is most often caused by mutations (genetic changes) in the breast cancer 1 (BRCA1) and breast cancer 2 (BRCA2) genes. Mutations in other, less common genes have also been associated with HBOC. However, most breast and ovarian cancers are not related to HBOC. In fact, only about 3 of every 100 breast cancers and 10 of every 100 ovarian cancers are caused by BRCA1 and BRCA2 mutations.


If you have a BRCA mutation, you are much more likely to get certain cancers:

  • Up to a 65% risk (about 6 out of 10) for breast cancer by age 70
  • Up to a 39% risk (about 4 out of 10) for ovarian cancer by age 70
  • Increased risks for other cancers including prostate, pancreatic, and male breast cancers

If you are found to have HBOC, steps can be taken to reduce your cancer risks, including:

  • Having earlier, more frequent, and/or additional cancer screenings
  • Taking medications that can decrease the risk of cancer
  • Undergoing preventive surgery to remove your breasts, ovaries, and fallopian tubes


HBOC can be passed down from either side of your family. An expert panel* recommends that doctors screen women who have family members with breast, ovarian, tubal, or peritoneal cancer with one of several screening tools designed to identify families that are more likely to have a BRCA mutation. You should let your doctor know if you have a personal or family history of any of the following:

  • Breast cancer at age 45 or younger in women
  • Breast cancer at age 46–50 or younger in women and at least one close blood relative with breast cancer at any age or limited family history
  • Triple negative** breast cancer at age 60 or younger in women
  • Breast cancer at any age in men
  • Ovarian, fallopian tube, or primary peritoneal cancer
  • Cancer in both breasts
  • Pancreatic cancer or prostate cancer with Gleason score ≥7 (Gleason score is a measure of the grade of the cancer)
  • Breast, ovarian, pancreatic, or prostate cancer among multiple blood relatives
  • Ashkenazi (Eastern European) Jewish ancestry
  • A known BRCA mutation in the family


If you are concerned about your personal or family history of cancer, talk to your doctor. Your doctor may refer you to a genetic counselor or other healthcare professional to discuss the benefits and risks of genetic testing for HBOC. BRCA genetic counseling and testing is often, but not always, covered without cost sharing by many health plans under the Affordable Care Act.
It is best if the first person in the family to get genetic testing is one of the family members who has had breast or ovarian cancer. If you or a family member are found to have a BRCA mutation, other blood relatives (siblings, children, parents, grandparents, aunts, uncles, and more distantly related family members) could also have this mutation and should consider genetic counseling and testing.

* U.S. Preventive Services Task Force (USPSTF)
**Triple negative tumors lack estrogen receptors, progesterone receptors and human epidermal growth factor receptor 2 (HER2).
This factsheet is a modified version of the Patient Information Sheet for Hereditary Breast and Ovarian Cancer created in 2012 by the Connecticut Department of Public Health’s Genomics Office in partnership with the Connecticut Tumor Registry.