Why biomarkers matter
Knowing your colorectal cancer biomarkers helps your doctor choose the most effective treatment plan while avoiding treatments that may not work for you.
What is biomarker testing?
You had probably never even heard of biomarkers until your cancer diagnosis, but they're a very important part of treatment planning.
Colorectal cancer biomarkers can be detected and measured in your body in a number of ways. The type of biomarker test you receive will depend on what your doctor decides is right for the type and stage of cancer you have.
Biomarker testing is usually done by taking a sample of your tumor (“tissue biopsy”) or your blood (“liquid biopsy”). This can be done at your doctor’s office or during a surgery.
The sample will be sent to a certified pathology laboratory where tests are done to find any abnormalities in the DNA, RNA, hormones, or proteins made by your cancer.
Other names for biomarker testing include molecular testing, genomic testing, tumor gene testing, and mutation testing.
Many kinds of tests are used, such as
- DNA or RNA sequencing
- next-gen sequencing
- molecular testing
- ctDNA
- immunohistochemistry
- FISH
What is a biomarker?
Biomarkers, short for biological markers or molecular markers, have characteristics that enable them to be measured and evaluated as an indicator of normal processes, pathogenic processes, or pharmacologic responses to a therapeutic intervention.
Biomarkers include DNA, proteins, and genetic mutations found in blood, tissue, or other body fluids.
Your biomarker profile can help you and your doctor personalize your treatment.
Biomarkers for colorectal cancer are used for diagnosis, progression, prognosis, and for treatment planning.
- Diagnostic biomarkers detect the disease
- Prognostic biomarkers are associated with a clinical outcome regardless of the treatment received
- Predictive biomarkers can predict the benefit or lack of benefit of a treatment
How are biomarkers tested?
Colorectal cancer biomarkers can be detected and measured in your body in a number of ways. The type of biomarker test you receive will depend on what your doctor decides is right for the type and stage of cancer you have.
Biomarker testing is usually done in one of two ways:
- A liquid biopsy, which is done by taking a blood sample.
- A tissue biopsy, which takes a sample of cells or tissues from the tumor.
The biopsy will be sent to a laboratory where a pathologist will run certain tests to find any abnormalities in the DNA, RNA, hormones, or proteins in the sample. The pathologist will then send a report to your doctor about the test results.
Once testing is complete, your doctor will be able to create a personalized treatment plan based on your unique biomarker traits.
Why is biomarker testing important?
Biomarker testing reveals very detailed information about your tumor. Your doctor will look at your test results to determine which specific biomarkers are present. The doctor may also see how much of the biomarker is present.
Biomarkers can also determine if your colorectal cancer has a hereditary genetic mutation or an acquired one. Only 5% of colorectal cancer cases are caused by hereditary mutations, which are called germline mutations. These genetic abnormalities are passed down from parent to offspring.
That means that 95% of colorectal cancers happen randomly due to somatic mutations (changes in body cells that you didn’t inherit). A somatic mutation means the body acquires the genetic abnormality for reasons researchers still don’t fully understand.
Biomarker testing is useful in both early and advanced (metastatic) colorectal cancer.
For patients with advanced cancer, biomarker testing is used to learn whether your cancer has any targetable characteristics. If it does, targeted therapy or immunotherapy may be a treatment option. These medicines work by targeting the specific characteristics of a tumor. The results of biomarker testing can also be used to determine whether you meet the criteria for joining certain clinical trials.
All of this information can help you and your doctor determine the most effective treatment plan for your unique tumor characteristics, while avoiding any treatment that may not work for you.
When should I have biomarker testing?
Depending on the biomarkers to be tested, testing could be done at different points during your colorectal cancer diagnosis, treatment, and follow-up care.
Good questions to ask your doctor
As a colorectal cancer patient, there are some important questions to ask your doctor about biomarkers:
- Have I had biomarker testing?
- What is my biomarker profile?
- How does my biomarker profile affect my treatment plan?
- What do these results mean for my prognosis?
World-class care
The Alliance and Perthera have partnered to provide personalized treatment options to patients with colorectal cancer. The Personalized Treatment Program (PTP) gives stage III and IV patients access to personalized treatment found at top cancer centers, no matter where they live.
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