What is the BRCA gene test?
BRCA gene test is a type of blood test done to detect changes (mutation) in the genes BRCA1 and BRCA2. These genes help in normal growth and development. Changes or mutation of these genes may indicate a greater risk of developing breast and ovarian cancer. Genetic mutation is the main cause behind all types of cancer. It may be acquired during the course of life but is more often inherited.
This gene test is not routinely performed on women but it is recommended in people who are considered to be high risk, like women with a personal or family history of breast and ovarian cancer. These mutations are quite uncommon. About 5% patients with breast cancer and 10 to 15% of women with ovarian cancer have inherited BRCA gene mutations. Genetic counseling is an essential part of BRCA gene testing.
BRCA Genetic Mutations
Mutation of the BRCA 1 or BRCA 2 genes increases the risk of developing breast and ovarian cancer in comparison to women in the general population who do not have these mutations. It has also been established that even men with BRCA mutation are at increased risk of suffering from breast cancer. Apart from breast and ovarian cancer, BRCA mutations also increases the risk of developing cancer of other organs in both men and women.
Who should have BRCA Gene Testing?
Testing should be done in women who considered at high risk of having BRCA mutations due to inheritance. This includes women with:
- Past history of suffering from breast cancer diagnosed before menopause.
- Past or present breast cancer in both breasts.
- A history of ovarian cancer.
- A relative suffering from ovarian cancer and or breast cancer at a very young age.
- Past history of breast cancer in two or more close relatives like siblings, parents or offspring.
- Male relative suffering from breast cancer.
- Relatives with known mutations of the BRCA genes.
- A Jewish ancestry with breast or ovarian cancer or both.
Under ideal conditions, the youngest family member with breast cancer should have the BRCA gene test at first. If this candidate shows negative result in BRCA gene testing then the test is not required in other family members.
Genetic counseling is the first step prior The counselor records a detailed family and medical history, discusses the risks with the candidate, limitations of the test, benefits of undergoing genetic testing and the options for cancer treatment. Before meeting with counselor the candidate should collect an extensive medical history from their family doctor, a family history from close relatives, documentation of personal medical history including results of past genetic testing, if any. Sometimes the BRCA gene test may fail to provide conclusive result.
BRCA gene testing is a type of blood test. A doctor, nurse or medical technician draws blood from the vein usually in the arm. This blood sample is then sent to a laboratory for DNA analysis. It usually takes several weeks to get the results but it may be available sooner in certain locations. The genetic counselor or doctor will discess the results with the candidate. It is important to remember that these mutations are uncommon even among breast and ovarian cancer patients. A positive result does not guarantee that a women will develop cancer but they are at a greater risk and should be more cautious than usual.