What are biomarkers?
In the context of colorectal cancer, biomarkers are typically proteins or molecules released by a tumor, or proteins or molecules that are part of a body’s response to the presence of cancer. They can be found in blood, other bodily fluids, or tissues.
In colorectal cancer, biomarkers may include gene changes that may give rise to mutated proteins in cancer cells. Gene changes may include mutations and are of 2 kinds.
- Gene changes that arise in cancer cells – these include somatic mutations; 95% of colorectal cancer may arise due to somatic mutations.
- Gene changes that are hereditary – these are called germline mutations, and account for 5% of colorectal cancer.
All colorectal cancer patients should be tested for the MMR (Mismatch Repair) status. 80-85% of crc patients are “MSS” (Micro satellite Stable), and the remainder are “MSI-H” (micro satellite Instable). This is important baseline information to know about your cancer as it can determine what treatments are effective.
This Learning Center focuses on additional biomarker testing for biomarkers beyond MSS. Researchers continue to discover new biomarkers, and develop therapies that target these biomarkers.
What information can biomarker testing provide?
Results from biomarker testing can be predictive or prognostic. Predictive results provide information on the potential effects of targeted therapies or the likelihood of toxicity to treatment. Prognostic results provide information on the potential overall outcome of the cancer diagnosis.
Biomarker testing can provide personalized information, which can be used to:
- Gain a better understanding of the prognosis of your cancer diagnosis
- Help predict how your cancer may or may not respond to a particular treatment
- Guide treatment decisions
- Anticipate a potential toxic response to treatment
- Monitor cancer for reoccurrence
This overview was adapted from the Know Your Biomarker campaign created by the Global Colon Cancer Association.