Genetic testing looks for alterations in your DNA, often known as mutations. Genetic testing can help you or your family member receive better treatment. The testing provides information for diagnosis, treatment and prevention. A blood or saliva sample is used for gene tests, and the reports are usually available in few weeks. Because we share DNA with our family members, if you have a genetic mutation, it is possible that your family members may also have.
Types of Gene testing for Breast Cancer
The BRCA gene test is done to identify breast cancer risk. This gene test is a type of blood test that uses DNA analysis to find mutations. The mutations are in either of the breast cancer susceptible genes- BRCA 1 or BRCA 2. Individuals inheriting mutations in these genes are at high risk of developing breast cancer.
The BRCA gene test is recommended for people who have a personal or family history of breast cancer. For individuals with average-risk for breast cancers, the BRCA gene test is not done. A positive result indicates that you carry gene mutation that increases risk for breast cancer. A negative result indicates that either you don’t have the mutation or you have a mutation that is not discovered yet.
Who is eligible for gene testing?
You may be at higher risk of having an inherited gene mutation that increases the risk of breast cancers, if you have:
- Two or more blood relatives diagnosed with breast or ovarian cancer begore age 45.
- Diagnosed with breast or ovarian cancer before menopause and have a blood relative with ovarian or breast cancer.
- A male in family diagnosed with breast cancer.
- You or your family diagnosed with bilateral (both) breasts cancer.
- Someone in family having BRCA1 and BRCA 2 mutations.
- Diagnosed with triple negative breast cancer.
- Personal history of ovarian, prostate or pancreatic cancer.
In a family with a gene mutation, the BRCA gene test should be done initially on a family member who has breast or ovarian cancer. Other genetic testing may also be considered for testing. Based on your personal and family history, a genetic counsellor can help you decide what alternative genetic testing choices are available.
Genetic testing isn’t completely reliable. Even if a test comes out negative, a person is still at risk of developing breast cancer. If the test is positive, there is still a 15% to 20% chance that you will not get breast cancer. However, the test can help you take precautionary measures to prevent breast cancer.
References:
- Genetic testing. Centers for disease control and prevention.
https://www.cdc.gov/genomics/gtesting/genetic_testing.htm - Genetic testing. MAYOCLINIC.
https://www.mayoclinic.org/tests-procedures/genetic-testing/about/pac-20384827 - Genetic testing for cancer risk. Cancer.Net.
https://www.cancer.net/navigating-cancer-care/cancer-basics/genetics/genetic-testing-cancer-risk - BRCA gene test for breast and ovarian cancer risk. MAYOCLINIC.
https://www.mayoclinic.org/tests-procedures/brca-gene-test/about/pac-20384815#:~:text=The%20BRCA%20gene%20test%20is%20a%20blood%20test%20that’s%20done,Breast%20cancer - Breast cancer and genetic testing. WebMD.
https://www.webmd.com/breast-cancer/guide/genetic-testing-risk