Genetic Testing vs Biomarker Testing vs Commercial DNA

Advances in genetic technology have improved how your medical team approaches cancer diagnosis and treatment. For patients with colorectal cancer, genetic testing and biomarker testing can help guide clinical decisions. These two complementary types provide critical information about a patient’s cancer and overall health.

Genetic testing looks at inherited DNA changes, helping to identify whether a person has an increased risk for developing colorectal cancer due to hereditary syndromes like Lynch syndrome, familial adenomatous polyposis (FAP), or others. Biomarker testing, on the other hand, focuses on traits of the tumor itself. This information can shed light on prognosis and help guide targeted treatment strategies.

Understanding the differences between these two types of testing can empower patients and their care teams. For individuals facing a colorectal cancer diagnosis, these tests can mean the difference between a one-size-fits-all approach and a tailored treatment plan with the potential for better outcomes and fewer side effects.

Let’s take a look at what genetic testing is (and isn’t) and how it compares to biomarker testing, and even the role commercially available DNA test kits may have in the process.

How are each of these used?

Genetic Testing

Genetic testing is done with the support of a genetic counselor and used to diagnose inherited or other medical conditions. Genetic testing can help with health care decision-making either before or after a diagnosis.
  • Identifies genetic disorders or genetic mutations linked to diseases.
  • Identifies a predisposition to – or elevated risk for – specific diseases and other health conditions, or inherited cancer syndromes including those related to colorectal and other cancers.
  • Guides health care providers with treatment decisions and can offer personalized healthcare strategies based on an individual’s genetics.
  • Examines specific genetic variations linked to disease risk, including cancer.

Information Provided: Results specific to genetic mutations and diseases
Sample Collection:  Blood, cheek swab, or saliva
Use: Clinical diagnosis, disease predisposition
Interpretation: Professional medical interpretation required
Clinical or Medical Relevance: Used specifically to diagnose specific inherited syndromes and making clinical decisions about health care, screening, and disease monitoring
Cost and Accessibility: Can be expensive, but is often covered by insurance. Requires healthcare provider referral/order

Biomarker Testing

Biomarker testing looks at an individual’s specific cancer tumor DNA to help guide personalized treatment and monitor effectiveness.
  • Also known as tumor testing.
  • Involves taking a tissue (often via biopsy) or blood sample to identify the presence of specific molecules or genetic mutations.
  • Looks for DNA mutations, RNA levels, or proteins present in a patient’s tumor to provide insights into the type of cancer, how the cancer may behave, and how it might respond to treatment.
  • Guides treatment decisions by identifying specific mutations or alterations in cancer cells that may affect an individual’s response to chemotherapy, immunotherapy, and other types of treatment; can also help identify clinical trials that may be beneficial for a patient to consider

Information Provided: Limited focus to cancer-specific cancer traits, prognosis, and treatment
Sample Collection: Tumor tissue biopsy or blood test
Use: Cancer diagnosis, monitoring, and treatment decisions
Interpretation: Professional medical interpretation required, including an oncologist for treatment planning
Clinical or Medical Relevance: Directly affects cancer treatment options and prognosis. Can diagnose cancer, predict treatment response, and personalize cancer therapy
Cost and Accessibility: Often costly and may be limited to specific cancers or treatment settings. Covered by insurance. Requires healthcare provider referral/order

Commercial DNA Testing

Commerical DNA tests analyzes general information about your genetic makeup. It is not meant for diagnosing diseases. (23andMe , Ancestry, and others)
  • For personal knowledge only, limited clinical value.
  • Provides individuals with information about their genetic makeup, including ancestry, health risks, inherited traits, or genetic predispositions to certain conditions.
  • Results are not specific enough to diagnose disease, and they lack oversight by a healthcare provider.
  • Personal data uncovered is owned by a private company, so privacy concerns may exist.

Information Provided: Broad, general genetic information
Sample Collection: Saliva or cheek swab
Use: Ancestry information and family trees, limited health risk information
Interpretation: General, non-clinical advice
Clinical or Medical Relevance:  For personal knowledge only. This personalized information on genetics, individual traits, and ancestry provides limited information for certain health risks
Cost and Accessibility: Generally affordable and widely available; can be ordered directly, without a prescription of physician order needed