Test Overview
A breast cancer
(BRCA) gene test is a blood test to check for specific changes (mutations) in
genes that help control normal cell growth. Finding changes in these genes,
called BRCA1 and BRCA2, can help determine your chance of developing
breast cancer and
ovarian cancer. A BRCA gene test does not test for
cancer itself. This test is only done for people with a strong family history
of breast cancer or ovarian cancer, and sometimes for those who already have
one of these diseases.
Genetic counseling before and after a BRCA test is
very important to help you understand the benefits, risks, and possible
outcomes of the test.
A woman's risk of breast or ovarian cancer
is higher if she has BRCA1 or BRCA2 gene changes. Breast cancer is extremely
rare in men but BRCA2 gene changes have been linked to male breast cancer and
possibly
prostate cancer. The risk of some other cancers,
including
pancreatic and colon cancer, may also be
higher.1 The gene changes can be inherited from either
your mother's or father's side of the family.
Certain people have
a higher chance of inheriting BRCA1 or BRCA2 gene changes.
- Jewish women are more likely to be BRCA gene
carriers. Some experts recommend gene tests for women who are Ashkenazi Jews
(Jews whose ancestors came from Eastern Europe) if they have one or both of the
following:2
- Any first-degree relative with breast or ovarian cancer.
First-degree relatives are parents, sisters and brothers, and
children.
- Two second-degree relatives on the same side of the
family with breast or ovarian cancer. Second-degree relatives are aunts and
uncles, nieces and nephews, and grandparents.
- If you are not Jewish, some experts recommend a
gene test if you have one or more of the following:2
- Two first-degree relatives with breast cancer, one of whom
was diagnosed before age 50
- Three or more first- or second-degree
relatives with breast cancer, diagnosed at any age
- Both breast and
ovarian cancer in the family
- A first-degree relative with cancer in
both breasts
- Two or more relatives with ovarian
cancer
- One relative with both breast and ovarian
cancer
- A male relative with breast cancer
National Cancer Institute (2002). Genetic testing for BRCA1 and BRCA2: It's your choice. Available online: http://www.cancer.gov/cancertopics/factsheet/Risk/BRCA.
U.S. Preventive Services Task Force (2005). Genetic
risk assessment and BRCA mutation testing for breast and ovarian cancer
susceptibility: Recommendation statement. Annals of Internal Medicine, 143(5): 355–361.
National Cancer Institute (2007). Genetics of Breast and Ovarian Cancer (PDQ)—Health
Professional Version. Available online:
http://www.cancer.gov/cancertopics/pdq/genetics/breast-and-ovarian/healthprofessional.