Biomarker tests can make an impact on colorectal cancer.
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 colorectal cancer. Talk to your doctor about testing to see what they may mean.
About biomarker testing
What are CRC 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 CRC 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. In CRC, a few biomarkers to be aware of are KRAS, NRAS, and BRAF.
Here’s how they’re tested.
Tissue Biopsies
A tissue biopsy is the first strategy in CRC cases. The procedure involves collecting a small piece of a tumor for closer examination.
Bits of tissue called polyps are removed using small tools passed through an endoscope during a colonoscopy. A pathologist then examines the samples in a lab. They’ll measure how much your cancer has progressed, look for gene and protein mutations that could point to targeted therapies, and check if immunotherapy may work for you.
Tissue biopsies are usually an outpatient procedure and do not require an overnight stay, however there are more invasive tissue biopsies that may require a hospital visit.
Liquid Biopsies
Liquid biopsies analyze traces of cancer found in blood, urine, cerebrospinal fluid, and saliva. For CRC, it usually involves a blood sample.
Simpler samples, especially urine or blood, can usually be taken at a clinic or your doctor’s office. Since these types of biopsies are less invasive, they’re also faster to complete and more easily repeated than a tissue biopsy.
While liquid biopsies can provide similar insights as tissue testing, it still has its limits — the results may not always match tissue biopsies and may miss some cancer changes.
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Talk to your doctor
Your tailored treatment plan really begins with a conversation.
When it comes to treating your CRC, 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 colorectal cancer?
Some important colorectal cancer (CRC) biomarkers are KRAS/NRAS, BRAF, and HER2. However, 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 liquid biopsy or tissue biopsy.
A tissue biopsy is typically the first strategy in CRC cases. It is usually an outpatient procedure and does not require an overnight stay, however there are more invasive tissue biopsies that may require a hospital visit. The procedure can involve surgically collecting bits of tissue, called polyps, using small tools passed through an endoscope during a colonoscopy. They're then sent to a specialized lab for analysis before being sent back to your care team.
In CRC, liquid biopsies analyze traces of cancer cells found in blood, urine, cerebrospinal fluid, and saliva. Simpler, less invasive samples, especially urine or blood, can usually be taken at a clinic or your doctor’s office.
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 colorectal 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://colorectalcancer.org
https://www.globalcca.org
https://fightcolorectalcancer.org