Table of ContentsView AllTable of ContentsWhat Are BRCA Genes?BRCA MutationsBreast Cancer RiskEffect on Cancer TreatmentGenetic TestingA Word From Verywell
Table of ContentsView All
View All
Table of Contents
What Are BRCA Genes?
BRCA Mutations
Breast Cancer Risk
Effect on Cancer Treatment
Genetic Testing
A Word From Verywell
Several genes have been linked tobreast cancer, the most common of which are BRCA mutations (BRCA1 and BRCA2). To give you a sense of their significance, the overall lifetime risk of breast cancer in women without a BRCA mutation is around 12%. For those with such a mutation, the average lifetime risk of developing breast cancer varies between 40% to 70%. BRCA mutations increase the risk of several other types of cancer as well.
Since a BRCA mutation is such a significant risk factor, many women with a family history of the disease are encouraged to get genetic testing. Such testing is not routine and requires thoughtful consideration about potential next steps. The possibility of discovering a predisposition to breast cancer can be frightening, but surveillance and treatment can improve the long-term survival of people who have these mutations, and this should temper some of your fears.
Verywell / Gary Ferster
The Role of BRCA Genes
Genes, which are inside each cell in your body, are made of DNA molecules. They are a blueprint—coding for the proteins that your body builds. BRCA genes are normal genes that function astumor suppressor genes. Each of your cells contains two copies of the BRCA1 gene and two copies of the BRCA2 gene (one copy of each from your mother and one copy from your father).
Normal BRCA genes code for proteins that prevent cancer growth, especially breast cancer and ovarian cancer. Specifically, these proteins are responsible for repairing cancer-causing damage to DNA in your cells.
What Is Oncogenesis?
BRCA Genes Mutations
Mutations are genetic errors. BRCA gene mutations are autosomal dominant, meaning that having one copy of the abnormal gene impairs their normal anti-cancer effect.
It is far more common to have only one mutated BRCA gene (this is written as BRCA1/2) than two of them.
There are two ways for a person to have a BRCA gene mutation:
Having a BRCA mutation gives you agenetic predispositionto cancer, but it does not mean that you will definitely develop cancer.
BRCA mutations areassociated with hereditary breast cancer, but not all hereditary breast cancers are due to BRCA mutations.
Additionally, in men,BRCA2 mutationsincrease the lifetime risk of breast cancer from 0.1% to around 7-8%.Overall, BRCA mutations account for 20% to 25% of hereditary breast cancers and 5% to 10% of breast cancers overall.
Hereditary breast cancers not related to BRCA mutations are referred to as non-BRCA familial breast cancer or BRCAX. Gene mutations that are linked to breast cancer include those in ATM CDH1, CHEK2, PALB2, PTEN, STK11, and TP53. There are likely others, and research is ongoing.
In those under age 40, about 10% of breast cancers are associated with being BRCA-positive, and after age 40, approximately 5% of breast cancers are associated with a BRCA gene mutation.
Familial Breast Cancer
How BRCA Mutations Affect Breast Cancer Treatment
These mutations are associated with different tumor characteristics that can affect responsiveness to therapy. BRCA mutations tend to be associated with cancers that have a highertumor grade, which is a measure of the aggressiveness of the tumor.
Hormone Therapy
In addition, breast cancers in women with BRCA mutations (especially BRCA1) are less likely to have estrogen or progesterone receptors. These proteins on the surface of breast cancer cells cause tumors to grow when they bind with these hormones.
These mutations also are associated with breast cancer that is less likely to beHER2-positive.
Triple-negative breast cancers—which don’t have HER2 receptors, estrogen receptors, or progesterone receptors—are more common in women with BRCA mutations than in women without the mutation. This means that medications that are effective for hormone receptor-positive and HER2-positive breast cancers are not usually effective for treating these cancers, which can make them more difficult to treat.
Chemotherapy
Breast cancers in women with BRCA mutations tend to respond betterto neoadjuvantchemotherapy(chemotherapy prior to surgery) than those in women without these mutations.
Genetic Testing for BRCA Mutations
Overall,genetic testingfor breast cancer genes is not standard. However, it is often recommended for women who have a family history of breast cancer or who have personally had breast cancer at a young age.
While you might have medical indications for getting tested, this is an emotionally charged decision. You may be faced with major decisions if you test positive for BRCA genes orother breast cancer genes (often called non-BRCA gene mutations).
Many women want to get tested in every way possible, while others prefer to avoid knowing about their risks.
Considerations as you make a decision about getting tested:
Regardless of your decision about genetic testing, you need to get your recommendedmammograms.
Keep in mind that a negative test result (no identified breast cancer genes) does not mean that you will not get breast cancer. Likewise, testing positive doesn’t mean you will absolutely get breast cancer.
If You’re Positive
Having a positive result (an identified breast cancer gene) may mean that you need to have screening mammograms at a younger age (before age 40).
There are no clear-cut recommendations regarding treatment for positive genetic tests because many women with these results don’t develop breast cancer. There is no right or wrong decision. Whether or not to pursue treatment at this stage is a very personal decision that you have to make carefully based on your risk and preventative options.
Breast Cancer Prevention
At this stage, it is important that you think aboutbreast cancer prevention. Experts suggest that consuming antioxidants (found in fresh fruit and vegetables), avoiding preservatives, and not smoking can decrease your risk of all cancers.
Specific considerations for breast cancer prevention:
Types of Mastectomy Surgery
BRCA Mutations and Other CancersOvarian canceroccurs in roughly 1.3% of women in the general population. For those with BRCA1 mutations, 39% are expected to develop ovarian cancer, while 11% to 17% of those with a BRCA2 mutation will develop the disease.There are other cancers that can be associated with BRCA mutations as well, such as prostate cancer, pancreatic cancer, andlung cancer.
BRCA Mutations and Other Cancers
Ovarian canceroccurs in roughly 1.3% of women in the general population. For those with BRCA1 mutations, 39% are expected to develop ovarian cancer, while 11% to 17% of those with a BRCA2 mutation will develop the disease.There are other cancers that can be associated with BRCA mutations as well, such as prostate cancer, pancreatic cancer, andlung cancer.
Ovarian canceroccurs in roughly 1.3% of women in the general population. For those with BRCA1 mutations, 39% are expected to develop ovarian cancer, while 11% to 17% of those with a BRCA2 mutation will develop the disease.
There are other cancers that can be associated with BRCA mutations as well, such as prostate cancer, pancreatic cancer, andlung cancer.
Psychological Effects of a Positive Test
If you or a relative have tested positive, you may become overwhelmed with worry about breast cancer. This reaction is not usual, but you owe it to yourself to sort out your feelings about the issue. If you are pre-occupied with the risk of breast cancer, it can help to talk to a therapist who can listen to you and provide you with strategies to cope with your feelings and apprehensions.
Once you have your BRCA results, you can work with your healthcare provider and genetic counselor to decide on your next steps, which will include breast cancer screening and potentially other therapies, such as hormone therapy or surgery. Voice your concerns. Ask your questions. It’s important that you feel confident about what you do following BRCA testing.
1 SourceVerywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ibrahim M, Yadav S, Ogunleye F, Zakalik D.Male BRCA mutation carriers: clinical characteristics and cancer spectrum.BMC Cancer. 2018;18(1):179. Published 2018 Feb 13. doi:10.1186/s12885-018-4098-yAdditional ReadingKotsopoulos J.BRCAMutations and Breast Cancer Prevention.Cancers (Basel). 2018 Dec 19;10(12). pii: E524. doi: 10.3390/cancers10120524.Metcalfe K, Eisen A, Senter L, et al.International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation.Br J Cancer. 2019;121(1):15-21. doi:10.1038/s41416-019-0446-1Wunderle M, Gass P, Häberle L, Flesch VM, Rauh C, Bani MR, et al.BRCA mutations and their influence on pathological complete response and prognosis in a clinical cohort of neoadjuvantly treated breast cancer patients.Breast Cancer Res Treat. 2018 Aug;171(1):85-94. doi: 10.1007/s10549-018-4797-8
1 Source
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.Ibrahim M, Yadav S, Ogunleye F, Zakalik D.Male BRCA mutation carriers: clinical characteristics and cancer spectrum.BMC Cancer. 2018;18(1):179. Published 2018 Feb 13. doi:10.1186/s12885-018-4098-yAdditional ReadingKotsopoulos J.BRCAMutations and Breast Cancer Prevention.Cancers (Basel). 2018 Dec 19;10(12). pii: E524. doi: 10.3390/cancers10120524.Metcalfe K, Eisen A, Senter L, et al.International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation.Br J Cancer. 2019;121(1):15-21. doi:10.1038/s41416-019-0446-1Wunderle M, Gass P, Häberle L, Flesch VM, Rauh C, Bani MR, et al.BRCA mutations and their influence on pathological complete response and prognosis in a clinical cohort of neoadjuvantly treated breast cancer patients.Breast Cancer Res Treat. 2018 Aug;171(1):85-94. doi: 10.1007/s10549-018-4797-8
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read oureditorial processto learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
Ibrahim M, Yadav S, Ogunleye F, Zakalik D.Male BRCA mutation carriers: clinical characteristics and cancer spectrum.BMC Cancer. 2018;18(1):179. Published 2018 Feb 13. doi:10.1186/s12885-018-4098-y
Kotsopoulos J.BRCAMutations and Breast Cancer Prevention.Cancers (Basel). 2018 Dec 19;10(12). pii: E524. doi: 10.3390/cancers10120524.Metcalfe K, Eisen A, Senter L, et al.International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation.Br J Cancer. 2019;121(1):15-21. doi:10.1038/s41416-019-0446-1Wunderle M, Gass P, Häberle L, Flesch VM, Rauh C, Bani MR, et al.BRCA mutations and their influence on pathological complete response and prognosis in a clinical cohort of neoadjuvantly treated breast cancer patients.Breast Cancer Res Treat. 2018 Aug;171(1):85-94. doi: 10.1007/s10549-018-4797-8
Kotsopoulos J.BRCAMutations and Breast Cancer Prevention.Cancers (Basel). 2018 Dec 19;10(12). pii: E524. doi: 10.3390/cancers10120524.
Metcalfe K, Eisen A, Senter L, et al.International trends in the uptake of cancer risk reduction strategies in women with a BRCA1 or BRCA2 mutation.Br J Cancer. 2019;121(1):15-21. doi:10.1038/s41416-019-0446-1
Wunderle M, Gass P, Häberle L, Flesch VM, Rauh C, Bani MR, et al.BRCA mutations and their influence on pathological complete response and prognosis in a clinical cohort of neoadjuvantly treated breast cancer patients.Breast Cancer Res Treat. 2018 Aug;171(1):85-94. doi: 10.1007/s10549-018-4797-8
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