Breast cancer is a type of cancer that starts in the breast and can be in one or both breasts. The breast is an organ that sits on top of the upper ribs and chest muscles. The breast has many different parts such as lobules (the gland that makes breast milk), ducts, nipple, stroma (fat and connective tissue), blood vessels, and lymph vessels. These parts operate like a machine to function, and when cancer is present, it interferes with these processes in the female body. Men can also get breast cancer but it is not common.
BRCA Gene Testing
All women have BRCA1 and BRCA2 genes, but only some women have mutations in those genes. This “mutation” or change, can prevent genes from doing their job properly, and certain mutations in the BRCA genes make cells more likely to divide and change rapidly, which can lead to cancer.
Not every woman with a BRCA1 or BRCA2 gene mutation will get breast cancer, but having a gene mutation does put you at an increased risk. About 50% of women with a gene mutation will get breast cancer by the time they turn 70 years old, compared to only 7% of women in the general US population who do not have a gene mutation.
BRCA gene testing is done with a blood or saliva sample, which is taken in a lab, doctor’s office, hospital, or clinic and is then sent off to a lab that does this test. Usually, the results will take several weeks to get back. Genetic testing, no matter what the results are, can be very helpful for any woman in figuring out the next steps.
Genetic Testing for Breast Cancer Pros and Cons
If there is a known genetic mutation in your family, and your gene test comes back negative, it can provide you with some relief. However, you should still keep up with consistent testing and screenings, as you may still get breast cancer since it runs in your family.
A positive gene test can help you understand your risks of getting breast cancer, but it does not mean that you will get cancer. This can help you understand your risk and you can make choices on what to do to reduce your risk of getting cancer, as well as what testing and screening you should participate in to monitor your risks. Many of these choices include but are not limited to:
- Preventative surgical removal of the breasts to lower cancer risk.
- If you do get diagnosed with breast cancer, you and your doctor can use your genetic information when coming up with a treatment plan.
- Learning that you carry an abnormal gene linked to breast cancer, may inspire you and your family members to make lifestyle changes, family plans, and other decisions that can help lower your cancer risk.
Although there are many steps you can take to lower your cancer risk if your genetic test results come back positive, there are many drawbacks to keep in mind, including but not limited to:
- Removing breasts dramatically lowers the chance of getting cancer, however, surgery does not always get rid of every breast-related cell, so it is important to continue screenings.
- “Normal” test results don’t guarantee healthy genes. Many women have still gotten breast cancer without a known gene mutation.
- You may still not be able to detect breast cancer early, even if you do participate in regular exams and screenings. Some may be diagnosed with the later-stage disease despite their efforts in the best surveillance techniques.
- Testing positive for a known gene mutation that links to breast cancer may cause anxiety, depression, or anger in some people. Even though this gene mutation does not necessarily mean you will get cancer if knowing you have a gene mutation would bother you, it may not be the best thing for you, and you can continue more testing to monitor your cancer risk.
- Genetic testing may not answer all the questions. There may be other factors contributing to high cancer risk that researchers do not know about yet.
Breast Cancer Genetic Testing Criteria
About 5% to 10% of breast cancers are thought to be hereditary, caused by genetic mutations passed from parent to child. BRCA1 and BRCA2 are among the most well-known genes that can mutate and raise the risk of breast cancer. Women who inherit a mutation in any of these genes carry a much higher risk of developing breast cancer. Men with these mutations, especially in the BRCA2 gene, have an increased risk of breast cancer as well.
Among some other criteria, guidelines recommend genetic testing for breast cancer if:
- There is a known mutation in the family.
- Someone is diagnosed with breast cancer below the age of 50.
- Someone is diagnosed with two primary breast cancers.
- A first-degree female relative (mother or sister) was diagnosed with breast cancer below the age of 50.
- Two or more first-degree female relatives were diagnosed with breast cancer
- A man in your family has been diagnosed with breast cancer.
Is Genetic Testing for Breast Cancer Worth It?
In summary, genetic testing is beneficial to anyone with a family history of breast or ovarian cancer. The BCRA1 and BCRA2 genes normally protect you from getting these cancers, however, a mutation in these genes can prevent them from working properly. Genetic testing can help you and your family determine a gene mutation, which can help you decide what kind of testing and surveillance is needed to monitor your current status.
A positive result for gene mutation doesn’t always mean you will get breast cancer. However, it is helpful to know so that you may monitor yourself closely. Testing can also help other members of your family in knowing what steps they should take in their own cancer screening decisions.
How Accurate is Genetic Testing for Breast Cancer?
Genetic testing is not 100% accurate. Even with a positive result, there is still a 15% to 20% chance of not getting breast cancer. With a negative result, there is still a chance of getting breast cancer.