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BRCA1 and BRCA2

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Also known as: BRCA; Breast Cancer Susceptibility Genes 1 and 2
Formal name: Breast Cancer Gene 1 and Breast Cancer Gene 2

At a Glance

Why Get Tested?

To assess the risk of developing breast or ovarian cancer associated with inheriting mutations in the BRCA1 or BRCA2 genes

When to Get Tested?

When you or someone in your family has had breast cancer before the age of 50 or ovarian cancer at any age, is a male with breast cancer, or when a BRCA1 or BRCA2 mutation has been identified in a family member

Sample Required?

A blood sample drawn from a vein in your arm or an oral rinse that collects cells from your mouth

Test Preparation Needed?

None, but genetic counseling is strongly recommended.

The Test Sample

What is being tested?

BRCA1 and BRCA2 are two tumor suppressor genes. Normally, these genes help prevent cancer by producing proteins that suppress abnormal cell growth. Certain changes (mutations) in these genes affect their normal function, thereby potentially allowing cell growth to occur uncontrolled. This test detects mutations in these genes that are linked mainly with hereditary breast and ovarian cancers.

According to the American Cancer Society (ACS), about 225,000 women are diagnosed with invasive breast cancer each year and about 22,000 with ovarian cancer. Of these cancers, about 5-10% will be due to a harmful mutation in BRCA1 or BRCA2 genes. Men can also inherit an increased risk of developing breast cancer, occasionally from mutations in BRCA1, but primarily from mutations in the BRCA2 gene.

Women with inherited mutations in BRCA1 or BRCA2 have up to an 85% lifetime risk of developing breast cancer and a 30-50% lifetime risk of developing ovarian cancer. Men and women may be at slightly increased risk for other cancers as well. Breast cancer in women with inherited mutations is likely to develop at an earlier age, before menopause.

BRCA mutations are inherited and passed from generation to generation. Each person will have two copies of BRCA1 and BRCA2, one copy from each parent. Mutations may be present in either copy of the gene. The DNA in cells is used to detect mutations in the BRCA genes. Cells from the blood or cells from the mouth are the most easily accessible sources of that DNA.

How is the sample collected for testing?

The test for BRCA mutations is done on a blood sample collected by needle from a vein in the arm or from a special oral rinse that collects cells from the mouth. The test does not require surgical biopsy of breast or ovarian tissue.

NOTE: If undergoing medical tests makes you or someone you care for anxious, embarrassed, or even difficult to manage, you might consider reading one or more of the following articles: Coping with Test Pain, Discomfort, and Anxiety, Tips on Blood Testing, Tips to Help Children through Their Medical Tests, and Tips to Help the Elderly through Their Medical Tests.

Another article, Follow That Sample, provides a glimpse at the collection and processing of a blood sample and throat culture.

Is any test preparation needed to ensure the quality of the sample?

No test preparation is needed, but genetic counseling is strongly recommended.

The Test

Common Questions

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Article Sources

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NOTE: This article is based on research that utilizes the sources cited here as well as the collective experience of the Lab Tests Online Editorial Review Board. This article is periodically reviewed by the Editorial Board and may be updated as a result of the review. Any new sources cited will be added to the list and distinguished from the original sources used.

Sources Used in Current Review

Baudhuin, Linnea, PhD, DABMG. Assistant Professor of Laboratory Medicine, Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.

Katrina Kotzer, MS, Certified Genetic Counselor. Department of Laboratory Medicine and Pathology, Division of Clinical Biochemistry and Immunology, Mayo Clinic, Rochester, MN.

Brittany Thomas, MS, Certified Genetic Counselor. Department of Laboratory Medicine and Pathology, Division of Laboratory Genetics, Mayo Clinic, Rochester, MN.

McKinsey Goodenberger, CGC. Department of Laboratory Medicine and Pathology, Mayo Clinic, Rochester, MN.

Petrucelli, N. et. al. (Updated 2011 January 20). BRCA1 and BRCA2 Hereditary Breast and Ovarian Cancer. GeneReviews [On-line information]. Available online at http://www.ncbi.nlm.nih.gov/books/NBK1247/ through http://www.ncbi.nlm.nih.gov. Accessed October 2012.

Kolor, K. (2011 October 10). Hereditary Breast and Ovarian Cancer: BRCA and Your Patient. Medscape Today News [On-line information]. Available online at http://www.medscape.com/viewarticle/749018 through http://www.medscape.com. Accessed October 2012.

(Updated 2012 February 27). Learning About Breast Cancer. National Human Genome Research Institute [On-line information]. Available online at http://www.genome.gov/10000507 through http://www.genome.gov. Accessed October 2012.

(Updated 2012 May 21). Breast and Ovarian Cancer. National Human Genome Research Institute [On-line information]. Available online at http://www.genome.gov/27527603 through http://www.genome.gov. Accessed October 2012.

(Updated 2011 October 6). Genomics and Health, Quick Facts About Family Health History and Genetic Testing for Breast Cancer and Ovarian Cancer. CDC Public Health Genomics [On-line information]. Available online at http://www.cdc.gov/genomics/resources/diseases/breast_ovarian_cancer/quick_facts.htm#2 through http://www.cdc.gov. Accessed October 2012.

(Updated 2010 October 28). Hereditary Breast and Ovarian Cancer. CDC Features [On-line information]. Available online at http://www.cdc.gov/Features/HereditaryCancer/ through http://www.cdc.gov. Accessed October 2012.

Mayo Clinic staff (2011 January 18). Genetic testing for breast cancer: Psychological and social impact. MayoClinic.com [On-line information]. Available online at http://www.mayoclinic.com/health/genetic-testing/BR00014/METHOD=print through http://www.mayoclinic.com. Accessed October 2012.

Preidt, R. (2012 September 7). X-Rays May Up Breast Cancer Risk for Women With Certain Genes: Study, Chest radiation before age 30 might be a risk for those with BRCA1/BRCA2 mutations. MedlinePlus Health Day [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/news/fullstory_129037.html through http://www.nlm.nih.gov. Accessed October 2012.

(Updated Dec. 21, 2012) National Cancer Institute. Genetics of Breast and Ovarian Cancer. Available online at http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/HealthProfessional/page1 through http://www.cancer.gov. Accessed Feb 2013.

Sources Used in Previous Reviews

Fasouliotis SJ and Schenker JG. BRCA1 and BRCA2 Gene Mutations: Decision-Making Dilemmas Concerning Testing and Management. Obstetrical and Gynecological Survey 55(6); 373-384 (2000).

(2005 September 16, Revised). Overview: Breast Cancer. American Cancer Society [On-line information]. Available online at http://www.cancer.org/docroot/CRI/CRI_2_1x.asp?rnav=criov&dt=5 through http://www.cancer.org.

(2005 January 1, Revised). Overview: Ovarian Cancer. American Cancer Society [On-line information]. Available online at http://www.cancer.org/docroot/CRI/CRI_2_1x.asp?dt=33 through http://www.cancer.org.

(2005 September 5). Task Force Recommends Against Routine Testing for Genetic Risk of Breast or Ovarian Cancer in the General Population. Agency for Healthcare Research and Quality [On-line Press Release]. Available online at http://www.ahrq.gov/news/press/pr2005/brcagenpr.htm through http://www.ahrq.gov.

(2005 July 18, Updated). Fact Sheet on Genetic Testing for Breast and Ovarian Cancer Susceptibility. CDC Genomics and Disease Prevention [On-line information]. Available online at http://www.cdc.gov/genomics/info/factshts/breastcancer.htm through http://www.cdc.gov.

(2005 September). Genetic Risk Assessment and BRCA Mutation Testing for Breast and Ovarian Cancer Susceptibility. U.S. Preventive Services Task Force [On-line Press Release]. Available online at http://www.ahrq.gov/clinic/uspstf/uspsbrgen.htm through http://www.ahrq.gov.

Petrucelli, N. et. al. (2004 September 3). BRCA1 and BRCA2 Hereditary Breast/Ovarian Cancer]. GeneReviews [On-line information]. Available online through http://www.genetests.org.

Brown, A. (2005 September 23). Most Breast Cancers Not Linked to Ovarian Cancer. MedlinePlus Reuters Health Information, from Journal of the National Cancer Institute [On-line information]. Available online at http://www.nlm.nih.gov/medlineplus/news/fullstory_27070.html through http://www.nlm.nih.gov.

Brian E Ward, Ph.D. FACMG. Senior Vice President of Medical Services. Myriad Genetic Laboratories.

(Updated 2007 November 27) Fact Sheet on Genetic Testing for Breast and Ovarian Cancer Susceptibility. CDC, Office of Public Health Genomics [On-line information]. Available online at http://www.cdc.gov/genomics/training/perspectives/factshts/breastcancer.htm through http://www.cdc.gov. Accessed May 2009.

(Revised 2008 September 30). American Cancer Society [On-line information]. Available online through http://www.cancer.org. Accessed May 2009.

(2009 March 9). BRCA Results Influence Women's Views of Preventive Mastectomy American Cancer Society [On-line information]. Available online through http://www.cancer.org. Accessed May 2009.

(2009 February 24). Removal of Ovaries and Fallopian Tubes Cuts Cancer Risk for BRCA-1/2 Carriers. National Cancer Institute [On-line information]. Available online at http://www.cancer.gov/clinicaltrials/results/BRCA0209 through http://www.cancer.gov. Accessed May 2009.

(Updated 2009 February 25). Learning About Breast Cancer. National Human Genome Research Institute [On-line information]. Available online at http://www.genome.gov/page.cfm?pageID=10000507 through http://www.genome.gov. Accessed May 2009.

Afonso, N. (2009 March 4). Women at High Risk for Breast Cancer - What the Primary Care Provider Needs to Know. Medscape from Journal of the American Board of Family Medicine. Available online at http://www.medscape.com/viewarticle/586947 through http://www.medscape.com. Accessed May 2009.

Wu, A. (© 2006). Tietz Clinical Guide to Laboratory Tests, 4th Edition: Saunders Elsevier, St. Louis, MO. Pp 184-185.

(May 29, 2009) National Cancer Institute. BRCA1 and BRCA2: Cancer Risk and Genetic Testing. Available online at http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA through http://www.cancer.gov. Accessed November 2009.

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