At a Glance
Why Get Tested?
When to Get Tested?
If you have a strong family history of breast or ovarian cancer, following appropriate pre-test genetic counselling
A blood sample drawn from a vein in the arm
The Test Sample
What is being tested?
BRCA1 and BRCA2 are two tumour suppressor genes. Normally, these genes help prevent cancer by producing proteins that repair damage to DNA (the genetic material in a cell). Certain changes (mutations) in these genes disrupt the function of the protein product and are associated with hereditary breast and ovarian cancers.
According to Cancer Australia, about 13,000 women in Australia are diagnosed with breast cancer each year and about 1300 women with ovarian cancer. In most of these women, their cancers are sporadic, but about 5-10% of these women have a familial predisposition to breast/ovarian cancer. Approximately 20% of the familial breast/ovarian cancer (i.e. 1-2% overall) are due to a harmful mutation in the BRCA1 or BRCA2 gene. Men can also inherit an increased risk of developing breast cancer, occasionally from mutations in BRCA1, but primarily from mutations in the BRCA2 gene.
The BRCA1 and BRCA2 genes are present in every cell of the body. To detect mutations in the genes, DNA needs to be extracted from cells, and blood is the most easily accessible source 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. The test does not require surgical biopsy of breast or ovarian tissue.
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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.