Genetic testing is a type of laboratory test that provides specialized information about whether a person has an abnormality in their genes, such as a mutation.
The test is performed in a lab, typically with a sample of the patient’s blood or oral cells.
Some genetic mutations are linked to certain cancers, like the BRCA1 or BRCA2 genes in breast cancer.
Genetic testing can be useful for anyone with breast cancer, but it’s not required. Anyone can be tested if they want to be. Your oncology team can help you make the decision.
People who meet certain criteria are more likely to have a gene mutation. This includes:
- being under 50 years old
- having a strong family history of breast cancer
- having breast cancer in both breasts
- having triple-negative breast cancer
There are specialized treatment options for metastatic breast cancer patients who test positive for genetic mutations, so be sure to ask about genetic testing.
Treatment for breast cancer is tailored to each individual, including those who are metastatic. For metastatic patients with genetic mutations, there are unique treatment options.
For example, specialized treatments like the PI3-kinase (PI3K) inhibitors are available for people with a genetic mutation in the PIK3CA gene if they meet certain hormone-receptor criteria.
PARP inhibitors are an option for people with metastatic breast cancer with a BRCA1 or BRCA2 gene mutation. Clinical trials for these treatments are ongoing. Your doctor can let you know if you’re a candidate.
Certain features associated with a genetic mutation can be targeted with a unique medication known to impact the outcome.
Different genetic mutations are associated with various risks. One isn’t significantly “worse” than another, but your specific mutation directly affects the treatment you’ll get.
PIK3CA is a gene important for cell function. Abnormalities (i.e., mutations) in the gene don’t allow it to perform properly. Studies have shown this mutation is common in people with breast cancer. It’s recommended for some people, including those with metastatic breast cancer, to undergo gene testing to evaluate for this mutation.
If you have it, you may be a candidate for targeted therapy like a PI3K inhibitor, which specifically addresses the cause of the mutation.
Clinical trials are a good option for many people with metastatic breast cancer. A trial is meant to answer important questions about the best treatments. They may offer specialized access to protocols you may not be able to receive otherwise.
There can be risks with clinical trials. Known risks must be shared with you before starting. After you’re fully informed about the study and its risks, you must give permission before you start. The trial team regularly assesses risks and shares any new information.
There are risks to genetic testing in terms of people being presented with serious information about the status of their genes. This can cause emotional stress.
There can also be financial constraints depending on your insurance coverage. You’ll also need to consider how you’ll disclose the information to your family members. Your care team can help with this decision.
Positive test results may also indicate that you need a more extensive treatment plan.
It’s a good idea to discuss genetic testing with your doctor as early as possible after being diagnosed because the results take time to process.
Most genetic testing takes 2 to 4 weeks to get the results.
Typically, the doctor who ordered the test or a geneticist will go over the results with you. This may be done in person or over the phone.
It’s also commonly recommended to see a genetics counselor to review your results further.
Dr. Michelle Azu is a board-certified surgeon specializing in breast surgery and diseases of the breast. Dr. Azu graduated from the University of Missouri-Columbia in 2003 with her doctor of medicine degree. She currently serves as the director of breast surgical services for New York-Presbyterian/Lawrence Hospital. She also works as an assistant professor at both Columbia University Medical Center and Rutgers School of Public Health. In her spare time, Dr. Azu enjoys traveling and photography.