Biomarker testing can lead to precise breast cancer care.
It helps doctors move from one-size-fits-all care to personalized treatment plans, like targeted therapy — a type of cancer treatment that targets the ways cancer cells grow, divide, and spread. Even if you get tested and don’t have any biomarkers, that’s ok. It’s still important for getting your care team more informed and can help them evaluate treatment options.
Did you know?
Your treatment plan can be based on your biomarkers.
You may recognize some of these biomarkers from your own chart. There are many biomarkers for breast cancer. Talk to your doctor about testing to see what they may mean.
About biomarker testing
What are breast cancer biomarkers?
Cancer biomarkers are small signals in tumor cells, like gene changes or certain levels of proteins, that can show how your cancer behaves and how it may change, grow, or respond to treatment. Even two people with the same type of breast cancer can have very different biomarkers.
By testing for them, your care team can create an individualized treatment plan — and adjust it if the disease changes over time. Some common breast cancer biomarkers are HER2, estrogen and progesterone receptor proteins (ER and PR), and changes in genes such as PIK3CA.
Here’s how they’re tested.
Tissue Biopsies
One of the most common ways to test for breast cancer biomarkers is by collecting tumor tissue with a needle biopsy or surgery.
A tissue biopsy can find answers you can’t get any other way. By studying the tumor at a microscopic level, doctors can learn what's driving your cancer and if targeted therapies may help.
While needle biopsies don’t require an overnight stay, tissue sampling is a more invasive procedure that may require a hospital visit — but the clarity it brings can make a real difference in finding a treatment that fits your needs.
Liquid Biopsies
In breast cancer, a liquid biopsy can be taken with a simple blood draw. It's most often used for patients with metastatic breast cancer.
Metastatic breast cancer is when the cancer has traveled to other parts of the body. Biomarker testing can provide deeper insight into this advanced stage, and point to specific mutations that are causing changes in the metastatic disease.
Since liquid biopsies are less invasive, they’re faster to complete and easier to repeat than tissue biopsies. But they do have their limits. The results may not always match tissue tests and may miss some cancer changes in the metastatic disease.
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Talk to your doctor
Your tailored treatment plan really begins with a conversation.
When it comes to treating your breast cancer, asking about biomarker testing early can make a big impact on your care. Even if this process is unfamiliar, your doctor can help you understand your options and move forward with clarity.
Still have questions?
What biomarkers do doctors look for in breast cancer?
Some important biomarkers for breast cancer are estrogen receptor (ER), progesterone receptor (PR), and human epidermal growth factor receptor 2 (HER2) — but there are several other biomarkers that your doctor may test for as well.
Where do I go to get tested?
Where you begin biomarker testing will depend on your need for a tissue biopsy or a liquid biopsy.
One of the most common ways to test for breast cancer biomarkers is by collecting tumor tissue with a needle biopsy — an outpatient procedure that can be performed in a clinic or doctor's office. In certain cases, if surgery is needed it may require an overnight stay in the hospital.
A liquid biopsy is a simple blood draw that’s most often used for patients with metastatic or advanced breast cancer. Since liquid biopsies are less invasive, they usually happen in a doctor’s office, clinic, or hospital, with samples sent to a specialized lab for deeper evaluation.
What should I understand about my test results?
When you get your test results, your doctor will go over them with you to help you understand what they mean and how they can be used to determine your treatment options. You’ll most likely discuss:
- What biomarkers were found — or if no biomarkers showed up
- What treatment options match those specific biomarkers, and which ones may be available to you
- If there aren’t treatment matches — what potential clinical trials may be available for those biomarkers, or other treatment options
Will I need to get retested?
Depending on how well your current treatment is working, your doctor may want to have you retested for any changes to your disease and the biomarkers that may show up.
Since changes can occur over time, it can reveal the way your tumor is growing or changing, or if it’s developing a resistance to treatment.
New biomarkers can indicate alternative treatment options that may work more effectively.
Are there communities and advocacy groups I can join?
There are many patient advocacy and support groups in the breast cancer community. Here are a couple to get you started with connecting to other patients and caregivers, as well as resources to support you during your journey:
https://www.lbbc.org
https://www.breastcancer.org
https://myfaultygene.org/