Inherited Risk: The BRCA Gene Explained
Medically reviewed on Apr 26, 2017 by L. Anderson, PharmD.
What are BRCA1 and BRCA2 Genes?
The BReast CAncer susceptibility gene (BRCA1 and BRCA2) are genes in our body (we all have them) that slow down tumor (cancer) growth by repairing damaged genetic material (DNA). However, if these genes are altered (through a mutation), DNA damage may not be repaired. Cancer cells can grow more easily with mutations in either the BRCA1 or BRCA2 genes. Mutated BRCA genes can be inherited from mother, father, or both parents.
Women with a mutation in the BRCA1 or BRCA2 gene have a higher risk of developing breast cancer and ovarian cancer. There is also a smaller risk of developing other cancers due to this mutation, such as fallopian tube cancers, peritoneal cancers, and pancreatic cancers. Men may also have BRCA mutations and are at higher risk for breast cancer, prostate cancer, and pancreatic cancer.
Should I Be Worried About Inherited Breast or Ovarian Cancer?
In general, only about 5 to 10 percent of breast or ovarian cancers are due to inherited risks from your mother or father. Most cancers, including breast and ovarian cancers, are due to mutations that occur throughout your lifetime due to environmental toxins or chemicals, viruses, or some other unknown cause.
However, if you have strong family history of breast or ovarian cancer (mother, sister, daughter) or have a man in your family (father, brother, son) who has had breast cancer or prostate cancer you should be sure to explain this to your doctor, who can assess if you need genetic counseling. This is especially important if the family member was less than 50 years of age at the time of diagnosis. Multiple family members with these cancers and a single family member with multiple types of cancer may mean there is genetic link. Pancreatic and colon cancer can also be inherited through genes.
Why Is BRCA Testing Done?
Knowing if you have BRCA1 or BRCA2 mutation will give you the opportunity, in consultation with a certified genetic counselor, to make decisions about how to lower your risk for cancer.
Testing positive for BRCA gene mutation is not common. According to the US Preventive Services Task Force (USPSTF), these mutations occur in roughly 1 in 300 to 500 women (0.2 to 0.3%). However, in people with immediate family members who have been identified with BRCA gene mutations or have a pattern of certain cancers, testing might make sense.
Not everyone needs a BRCA test; in fact, most people do not. Your primary care physician will assess your need for genetic counseling. After meeting with the certified genetic counselor, testing may be recommended for those who have a personal or family history of breast, ovarian, or other cancers.
Should I Consider Getting Tested for the BRCA Gene?
The best way to determine if you should be tested for BRCA1 or BRCA2 mutation is to first talk with your primary care provider. There are special tools your doctor can use to help determine the need for genetic counseling. Actions from BRCA gene testing might include increased cancer screening, use of medications to lower your cancer risk, and even surgery.
BRCA testing can be an emotional roller coaster for some. However, for many, knowing their risk level and path forward is a relief. BRCA status can also be useful information for one's children - both boys and girls - when they grow older. In someone who has a BRCA mutation, their child will have a 50% chance (1 in 2) of inheriting the gene. As adults, your child may decide to undergo genetic counseling. BRCA testing is not recommended for children under 18 as pediatric cancers associated with these mutations are uncommon.
Am I At Risk for a BRCA Gene Mutation?
Screening tools are now available that health care providers can use to determine your likelihood of having a BRCA1 or BRCA2 gene mutation. These tools assess family risk factors, including:
- Breast cancer diagnosis before age 50
- Cancers in both breasts in women
- Breast and ovarian cancers in same woman or family
- Multiple breast cancers
- Two or more BRCA1 or BRCA2-related cancers in a single family member
- Occurrence of male breast cancer
- Ashkenazi Jewish (Eastern European) ethnicity with a family history of breast or ovarian cancer
How Is BRCA Testing Done?
It is preferable that BRCA testing be done in a family member that has been diagnosed with cancer, typically breast or ovarian. If a BRCA mutation is not found, testing of other family members is not usually done. However, if it is not possible to test a family member, and your risk is deemed high, BRCA testing is an option for you.
How do you prepare? The actual BRCA test is fairly straightforward and simple; a DNA sample from a blood test or a saliva test is used. Most often a blood sample is drawn from your arm. The sample is sent to a laboratory and the results can take several weeks. When your results are available, you will meet with your genetic counselor to discuss the results and determine next steps.
How Much Will Having a BRCA Gene Mutation Increase My Cancer Risk?
To determine how much impact a positive BRCA gene mutation might have, it's often helpful to compare with cancer risks in the general population first. Overall, in the general population, 12.3% of women (12.3 out of 100) will develop breast cancer in their lifetime, and 2.7% will die from the disease. Ovarian cancer is much lower in the general population: 1.4% of women will develop ovarian cancer and 1% will die.
However, in women with either BRCA gene mutation, their risk of breast cancer occurrence by age 70 ranges from 45% to 65%. Specific mutations in the BRCA1 gene increase the ovarian cancer risk to 39% by age 70, and BRCA2 mutation raise the ovarian risk to 10% to 17%. Studies have shown the rates of BRCA1 and BRCA2 mutations can be higher in Ashkenazi Jewish women. Based on these estimates supplied from the USPTSF, it's easy to see that women with BRCA mutations have a much higher risk for breast and ovarian cancers compared to the general population.
My BRCA Test is Positive. Now What?
A genetic counselor will help you to understand your tests results when they are available. Having a positive test does not mean you will definitely develop cancer; only that your risk is increased. Based on many different factors, including your family history, age, overall health, prior treatments, surgical history, and personal preferences, your options to lower cancer risk might include:
Options: More Frequent or Intensive Screenings
More frequent screenings are one option to help lower the risk from dying from certain cancers linked with a BRCA gene; however, screenings won't lower your risk for getting cancer.
Screenings typically include mammograms started at an earlier age, and mammograms and breast MRIs alternated every 6 months. A monthly self-breast exam should also be included.
Screening for ovarian cancer is not optimal and does not have a high success rate of identifying disease. However, ovarian cancer screening may be offered as an option, using a blood test known as CA-125 combined with a pelvic ultrasound every 6 months.
Option: Drug Therapy to Reduce Cancer Risk
Use of certain medications can lower the risk of developing cancer due to a BRCA gene. Tamoxifen and raloxifene (Evista) are approved to lower the risk of breast cancer occurrence in women in the general population at risk, but the effect in women with BRCA mutations is not fully known. In the general population, tamoxifen and raloxifene lower the risk of developing breast cancer by about 38 percent in women at risk, according to the American Cancer Society. Both drugs are approved by the FDA for use in high risk women, but not specifically for women with BRCA mutations.
Hormonal contraceptives such as the pill have also been shown to reduce ovarian cancer risk by about 50%, in the general population and in women with a BRCA mutation. However, there is a concern that hormonal contraceptives may also increase the risk of breast cancer, particularly in BRCA1 carriers.
Option: Preventive Surgery
With a prophylactic mastectomy (removal of both breasts), breast cancer risk can be reduced by at least 90 percent, according to studies.
In premenopausal women having a prophylactic salpingo-oophorectomy (removal of fallopian tubes and ovaries), the risk of ovarian and fallopian tube cancer is reduced by roughly 80% and breast cancer risk is lowered by at least half.
What If My BRCA Test Is Negative?
You should discuss any result, positive or negative, with your genetic counselor. Each case is individual, but in general, a negative BRCA test means you do not have a BRCA gene mutation.
However, that does not mean that you cannot get cancer either due to another hereditary risk factor or some other unknown reason. BRCA testing does not test for every genetic mutation.
If one of your close family members has a BRCA mutation, and your test is negative, this means that your risk for cancer is equivalent to the general population.
Is My Genetic Information Private?
One concern you may have about going forward with any type of genetic testing is your privacy. Your genetic information is protected under federal and state laws, and you cannot be denied health insurance based on your results.
The Genetic Information Nondiscrimination Act (GINA) is a federal law that prohibits health insurance and employers from using your genetic information. Your employers cannot fire you due to genetic testing, and your health insurance can't raise your rates or deny you coverage.
However other insurance, such as life, long-term, or disability insurance may not be subject to these privacy laws. You should consider discussing this important topic with your genetic counselor, who will have updated privacy laws and guidelines.
Is BRCA Testing Covered By Insurance?
The costs associated with BRCA testing can be substantial; however, if you meet the criteria to be at risk for a BRCA gene mutation, your insurance should cover your costs. In fact, The Affordable Care Act considers genetic counseling and BRCA1 and BRCA2 mutation testing for individuals at high risk a covered preventive service; how this might change going forward with the repeal of the ACA is not known yet.
Talk to your primary care provider about utilizing an in-office questionnaire to determine if you might be a candidate for genetic counseling and possible BRCA testing. Your insurance carrier can provider further criteria to your counselor or you to determine your share of costs, if any.
If you were to fully pay out-of-pocket for BRCA testing, the cost could range from $300 to $5000 depending upon the specific test ordered. If you cannot afford BRCA testing, but you need it, speak to your healthcare provider who can direct you to possible financial resources.
BRCA Gene Testing: Find Support
You may remember hearing about BRCA gene testing back in 2013 when American actress, director, and producer Angelina Jolie opened up about her decision to have a mastectomy in The New York Times. Jolie wrote an eloquent op-ed entitled "My Choice." She explained her medical background, her procedure in some detail, and that the decision was an individual and personal one, as it always should be.
However, a greater benefit of Jolie's story was the benefit that many women may have derived from learning about the BRCA genes, the BRCA test, and what the outcomes can be for those who face the decision to have surgery. While surgery is not the right option for everyone, studies have shown much higher rates of cancer prevention. Talk to your doctor. And keep the conversation going by joining the Drugs.com Support Groups for Breast Cancer and Ovarian Cancer. There you can stay on top of the latest cancer news, ask questions, and voice your opinion, too.
Finished: Inherited Risk: The BRCA Gene Explained
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- Final Update Summary: BRCA-Related Cancer: Risk Assessment, Genetic Counseling, and Genetic Testing. U.S. Preventive Services Task Force. July 2015. Accessed Feb. 13, 2017 at http://www.uspreventiveservicestaskforce.org/Page/Document/UpdateSummaryFinal/brca-related-cancer-risk-assessment-genetic-counseling-and-genetic-testing
- Peshkin B, Isaacs C. UpToDate. Patient information: Genetic testing for breast and ovarian cancer (Beyond the Basics). Accessed Feb. 13, 2017 at https://www.uptodate.com/contents/genetic-testing-for-breast-and-ovarian-cancer-beyond-the-basics
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