Genetics
Breast cancer: It’s all in the genes
Genes are inherited from our mother and father. We are born with them. You may have heard of the BRCA 1 and BRCA 2 breast cancer genes. Well, there are many other genes associated with breast cancer although they are not as common as the BRCA genes. You may carry one of these genes. Multi-gene or panel testing tests for BRCA 1 and 2 as well as the other genes associated with breast and other cancers (see RISK).
Genetic testing if you don’t have breast cancer
- Many women carry a breast cancer gene and don’t know it. Over time, some of these women go on to develop breast cancer. One of my goals is to improve access to genetic testing.
- Genetic testing simply involves coming to the office for a consultation and then spitting into a plastic test tube. The DNA is collected from your saliva. The test takes about 10 minutes to collect the sample and it’s painless. There are no needles and you don’t need to give blood. It takes 2 to 3 weeks to get the results. If you want genetic testing and meet the criteria, your insurance company should cover the cost of testing. If not, the cash price is about $250.
- If you had genetic testing before 2014, you might want to consider having an updated gene test. This is because our knowledge of genetics is constantly growing and testing prior to 2014 did not include testing for BRCA rearrangements, PALB2 and other mutations.
- If you end up having a mutation there are options to reduce the risk of cancer.
Dr. Miltenburg is uniquely suited to provide counseling on genetic testing, perform genetic panel testing in the office, interpret the results and lower your risk of developing breast cancer.
Genetic testing if you have breast cancer
- If you have breast cancer you should have genetic panel testing because the results will influence your treatment options and treatment influences prognosis (outcome).
Genetic testing if you have a relative or family member with a genetic mutation
- You should be tested for the specific mutation that your relative has. You will need a copy of their report. In this situation you do not need panel testing. Often times the genetic test company will do this for you for free.
If your genetic testing shows a Variant of Uncertain/Unknown Significance (VUS)
- A VUS means that an abnormal DNA sequence was detected but that it’s not associated with any known pathological process. This is possible because redundancy was built into the human genome. Not every single piece of DNA or string of DNA (sequence) is critical. This believed to be a safety feature. Things don’t always go perfectly according to plan every time DNA replicates and this can result in an abnormal sequence. If there is redundancy or repetition built into the system and something goes wrong, it doesn’t always necessarily end up in disease or cancer. Nothing at all might happen. It’s possible that a patient has a DNA sequence that is not “normal” but doesn’t have a negative consequence on his or her health. That is want a Variant of uncertain/unknown significance (VUS) is. Having said that, the gene testing company should continue to monitor variants of uncertain significance in case in the future, it’s discovered that a specific VUS is associated with disease. In that scenario, the patient should be notified (see RISK).
If you have breast cancer and negative genetic testing
- This is a common scenario: 90% of women who get breast cancer do not carry a gene mutation. In other words, the majority of women diagnosed with breast cancer did not inherit a cancer gene from one of their parents. In these patients we think several factors probably contributed to the development of cancer. This is an important point because many people think they won’t or can’t get breast cancer because it “doesn’t run in the family.” The truth is that most women who get breast cancer are the only ones in their family. So, one way to think about or categorize breast cancer is as hereditary (10%) or spontaneous (90%).