The Role of Genetic Testing in Cancer
There are currently two breast cancer genes recognized:
- BRCA 1
- BRCA 2
These genes are involved in DNA repair, and when certain mutations in these genes are present, the ability of a breast cell to repair its DNA is hampered, and the cell becomes prone to becoming cancerous. To date, nearly a thousand mutations in the BRCA 1 and BRCA 2 genes have been identified, and many of these have been found to be associated with a significantly increased risk of breast cancer and ovarian cancer.
Important Breast Cancer Facts
- In the United States, one in eight women will be diagnosed with breast cancer in their lifetime.
- The majority of breast cancers are not hereditary. Therefore, the absence of a family history of breast cancer does not preclude a woman from being diagnosed with breast cancer herself. Conversely, the presence of a family history of breast cancer does not necessarily mean that your cancer is hereditary. In order to determine whether or not there is a significant family history that may be suggestive of a hereditary predisposition, your doctor will ask a for a detailed cancer history of your family tree.
Certain patterns of cancer in a family may indicate the presence of a BRCA gene mutation. BRCA gene testing is a DNA test which can be performed on either a blood sample or saliva sample. Most insurance plans will cover all/part of the test expense if you meet the appropriate criteria. If you meet any of these criteria, your doctor will discuss genetic testing with you, or refer you to a genetic counselor, medical geneticist, oncologist, or other health professional with expertise and experience in cancer genetics.
Should I Do Genetic Testing?
Identification of a deleterious BRCA mutation may have significant implications on your future risk of a new breast cancer or ovarian cancer, and may be helpful in helping you and your doctors determine the best treatment option and follow-up/surveillance plan for you.
The NCCN (National Comprehensive Cancer Network) has published a set of guidelines to help doctors determine when genetic testing may be appropriate in a breast cancer patient.
- Early age onset breast cancer ≤ 50 years old
- Triple negative [ER(-) PR (-) HER2/neu (-)] breast cancer ≤ 60 years old
- Two breast cancer primaries in a single individual (at the same time, or at different times)
- Breast cancer at any age with: ≥ 1 close blood relative (1st, 2nd, 3rd degree) with breast cancer ≤ 50 years old, or ≥ 1 close blood relative (1st, 2nd, 3rd degree) with ovarian/fallopian tube cancer at any age, or ≥ 2 close blood relatives with breast cancer and/or pancreatic cancer at any age
- Ovarian/fallopian tube cancer
- Male breast cancer
- Ashkenazi Jewish descent