What is Hereditary Breast and Ovarian Cancer Syndrome (HBOC)?
Although multiple factors have been associated with increased risk for breast and
ovarian cancer, family history remains the most significant and consistent predictor
of disease development.(1-4). It is estimated that 2-7% of breast cancers, and 10-15%
of ovarian cancers are the result of an inherited mutation in one of two major hereditary
breast/ovarian cancer susceptibility genes, BRCA1 and BRCA2 (BRCA1/2). (5-11) Women who carry a mutation in one of the BRCA genes have a lifetime risk for breast cancer ranging
from 45-90%, with over half occurring under the age of 50.(11-16) The risk for ovarian
cancer in gene mutation carriers is as high as 30 fold that of the general population.
(9, 11-17, 16)
Family history clues that indicate a possible risk for HBOC include a personal or
family history of:
- Breast cancer diagnosed before the age of 50
- Ovarian cancer diagnosed at any age
- Both breast and ovarian cancer in the same person
- Bilateral or multiple primary breast cancers
- Ashkenazi Jewish heritage with a history of breast and/or ovarian cancer
- Presence of male breast cancer in the family
- A known BRCA1 or BRCA2 mutation identified in the family
- Breast cancer diagnosed prior to age 60 with triple negative pathology (ER -, PR
- ,HER2 -)
How will this knowledge benefit my patient?
- Potential benefits of identifying individuals at hereditary risk for breast and
ovarian cancer are well-documented (18-31) and include management options for BRCA1/2
mutation carries such as:
- Prophylactic mastectomy
- Bilateral salpingoophorectomy
- Breast MRI
- Identification of a BRCA1/2 mutation also allows for accurate testing of family
members to identify who is and is not at increased risk for cancer.
Should I refer my patient for cancer genetic counseling?
In 2005, the United States Preventive Services Task Force (USPSTF) determined that
sufficient evidence exists to recommend that "women whose family history is associated
with an increased risk for deleterious mutations in BRCA1 or BRCA2 genes be referred
for genetic counseling and evaluation for BRCA testing."(32)
Why use the B-RST™ tool for risk assessment?
USPSTF acknowledged the complexity of risk assessment and counseling patients about
BRCA1/2 testing and concluded: "It would be helpful to develop and validate tools
feasible for use in primary care practice that would help clinicians make appropriate
referrals for genetic counseling."(32) B-RST™ is such a tool as it is simple, quick
and provides accurate results in identifying individuals at potential risk for HBOC.
The B-RST™ tool was validated in a population of 2,464 unselected women undergoing
screening mammography. (33) When compared to complex models requiring detailed four-generation
family history information, B-RST™ demonstrated an overall discriminative accuracy
of 0.90 (95% CI 0.86-0.95) in identifying women with a ≥ 10% probability of carrying
a BRCA1/2 mutation (sensitivity 89%, specificity 92%). (34)
Click here to learn how the B-RST™ Score is interpreted
Note: B-RST™ is NOT designed to determine who
should be offered BRCA1/2 genetic testing, but to identify who should be referred
for a comprehensive cancer genetic counseling. Suitably trained healthcare providers
in cancer genetics can be found through links under resources.