Hereditary Breast and Ovarian Cancer: BRCA and Your Patient
Today I would like to talk to you about hereditary breast and ovarian cancer. I will describe how basic family history information can be used to help determine whether your patients might be at increased risk for hereditary breast and ovarian cancer and could benefit from genetic counseling and evaluation.
The US Preventive Services Task Force (USPSTF) issued a recommendation in 2005 that women whose family history indicates an increased risk for hereditary breast and ovarian cancer associated with mutations in the BRCA1 and BRCA2 genes be referred for genetic counseling and evaluation for BRCA genetic testing. This is a preventive service covered under the Affordable Care Act. Available research suggests that in the United States as many as 3 out of 4 women with relevant family histories who might benefit from genetic counseling for hereditary breast and ovarian cancer have not used these services.
Most breast and ovarian cancers that occur in women in the general population are not hereditary. Only 3%-5% of women who develop breast cancer and about 10%-15% of women who develop ovarian cancer have an associated BRCA1 or BRCA2 mutation. For women who have a BRCA mutation, the risk of developing breast or ovarian cancer is greatly increased, with current risk estimates ranging from 50%-85% for breast cancer and 10%-40% for ovarian cancer by age 70, and important steps can be taken to help lower risk for cancer in these women.
Women With BRCA Mutations Do Have OptionsFor women with BRCA mutations, the USPSTF found fair evidence that prophylactic bilateral mastectomy reduces breast cancer risk by 85% or more, and prophylactic oophorectomy reduces ovarian cancer risk by 85% or more and breast cancer risk by 53% or more. Thus, the potential benefits of genetics referral and evaluation for these women can be substantial. The USPSTF found insufficient evidence to determine the benefits of chemoprevention or intensive screening in improving health outcomes for these women. This continues to be an active area of research, and women who are at risk should carefully review their options with a healthcare provider knowledgeable about medical management of women with BRCA mutations.
How Can We Identify Women Who Might Be at Risk?Your patient might be at increased risk of having BRCA mutations if her family history includes one or more of the following in her first- or second-degree relatives (Remember that the maternal and paternal sides of the family are equally important.):
- Several relatives with either breast or ovarian cancer -- generally, 2 or more with ovarian cancer and 3 or more with breast cancers on the same side of the family;
- Breast cancer at a young age (under 50 years);
- A combination of breast and ovarian cancer among relatives;
- A relative with primary cancers of both breasts;
- A relative who had both breast and ovarian cancer;
- A male relative with breast cancer;
- Ashkenazi Jewish ancestry and any first-degree or 2 second-degree relatives with breast or ovarian cancer on the same side of the family; and
- A relative with a known BRCA mutation
While the USPSTF recommends genetic counseling and evaluation for BRCA testing for women whose family history is associated with an increased risk for BRCA mutations, it recommends against routine referral for women without an increased family history risk. It is also important to note that the USPSTF recommendations were focused on women without a personal history of breast or ovarian cancer. Women affected by these cancers may also benefit from genetic counseling and evaluation for BRCA testing.
In closing, remember that:
- Most of your patients aren't at increased risk for BRCA mutations, but patients with increased family history risk patterns as recommended by the USPSTF could benefit from genetic counseling and evaluation for BRCA testing;
- Genetic counseling by a suitably trained health care provider is important to help women make informed decisions about BRCA genetic testing;
- Women with BRCA mutations can take effective steps to lower their risk for breast cancer and ovarian cancer;
- Genetic testing for BRCA mutations will not find all causes of hereditary breast or ovarian cancer; and
- Health insurance often, but not always, covers the cost of genetic counseling and BRCA testing.
Table. Breast and Ovarian Cancer and Family History Risk Categories
|Risk Category||Family History*||Example||Effect on Cancer Risk||What You Can Do|
|Average||No first- or second-degree relatives with breast or ovarian cancer |
Just one second-degree female relative with cancer of one breast diagnosed after age 50
|Grandmother with breast cancer diagnosed at age 75||Typically not increased, similar to the general population risk|
|Moderate||Just one first-degree female relative with cancer of one breast (diagnosed at any age) |
Two first- or second-degree relatives (female) with cancer of one breast diagnosed after age 50
Just one first- or second-degree relative with ovarian cancer
|Mother with breast cancer diagnosed at age 68 and maternal aunt (mother's sister) with breast cancer diagnosed at 62 |
Sister with ovarian cancer
|Somewhat higher than the general population risk, but most women from these types of families will not develop breast or ovarian cancer||Taking action may be of greater benefit for women with a moderate vs average risk family history.|
|Strong||Two‡ or more first- or second-degree relatives with breast and/or ovarian cancer,if at least one breast cancer: ||Sister with breast cancer diagnosed at age 40, paternal aunt (father's sister) with breast cancer diagnosed at age 45, paternal grandmother (father's mother) with ovarian cancer||Not all women in these families will develop breast or ovarian cancer, but risk is much higher than general population|| |
*First-degree = parents, brothers, sisters, children; second-degree = aunts, uncles, nieces, nephews, grandparents, grandchildren
†For women of Jewish ancestry: Women who have a moderate family history but are of Ashkenazi (Eastern European) Jewish ancestry should talk with their health care provider about genetic counseling for cancer risk.
‡Risk category may also be strong if only 1 relative had:
- Cancer in both breasts diagnosed before age 50; or
- Both breast and ovarian cancer.
CDC: Quick Facts About Breast and Ovarian Cancer and BRCA1/2 Genes
CDC: Breast and Ovarian Cancer and Increased Risk Family History Patterns
USPSTF: Genetic Risk Assessment and BRCA Mutation Testing for Breast and Ovarian Cancer Susceptibility
CDC: Breast and Ovarian Cancer and Family Health History
Genetics Home Reference: Breast Cancer
Gene Reviews: BRCA1 and BRCA2 Hereditary Breast and Ovarian Cancer
National Cancer Institute: Genetics of Breast and Ovarian Cancer (PDQ®)
National Society of Genetic Counselors: Find a Genetic Counselor
NCI: Cancer Genetics Services Directory
CDC: Genetic Counseling and Evaluation for BRCA1/2 Testing
Healthy People 2020: Genomics Objectives
Katherine Kolor, PhD, CGC is a health scientist in CDC's Office of Public Health Genomics (OPHG), which serves as the national focus for integration of genomics into public health research and programs for disease prevention and health promotion. Dr. Kolor joined OPHG in 2005, and currently serves as a senior scientific advisor for public health scientific policy, planning and evaluation activities. Her efforts include assessing awareness and use of genetic tests among healthcare providers and the public through public health surveillance and surveys. Earlier in her career with OPHG, Dr. Kolor's efforts were focused on contributing to the EGAPP™ [Evaluation of Genomic Applications in Practice and Prevention] initiative to establish and test a systematic, evidence-based process for evaluating genetic tests and other applications of genomic technology that are in transition from research into clinical and public health practice. Dr. Kolor received her BS in Biology from the State University of New York at Albany, her PhD in Genetics from the University of Washington, and her MS in Human Genetics from Sarah Lawrence College. Dr. Kolor is a board-certified genetic counselor.