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Genetic testing for cancer includes several types of medical tests that analyze DNA. Some look for inherited gene changes that may increase cancer risk. Others examine the genetic features of a tumor to help guide treatment decisions. It is not one single test. They are a family of technologies, each designed for a specific clinical purpose and moment in your health journey.
For people focused on prevention, the most relevant type is hereditary cancer risk testing, which looks for inherited gene changes that increase your lifetime cancer risk, long before any diagnosis. This guide explains the major types of cancer genetic tests, what each is for, who they apply to, and how to access them.
Cancer genetic tests use DNA analysis to identify genetic factors that affect cancer risk or cancer behavior.
The term covers several fundamentally different types of tests that are often grouped but serve very different purposes.
The most important distinction is whether a test looks at your inherited DNA or at the DNA of cancer cells:
These three terms are often confused. Here is what each one actually means:
According to the American Cancer Society, 1 in 3 individuals will be diagnosed with cancer in their lifetime. Of those cases, 5–10% are caused by inherited gene changes that can be identified through hereditary cancer screening before any cancer develops.
That matters because of timing. Stage 1 localized cancer detection is associated with approximately 91% five-year survival rates, according to NCI SEER data, compared to approximately 30.6% when cancer has spread. Identifying inherited risk before a diagnosis creates the opportunity to detect cancer earlier, or to take protective steps before it has a chance to develop at all. (American Cancer Society, Family Cancer Syndromes)
A hereditary cancer risk panel analyzes DNA from a cheek swab, saliva sample, or blood draw to simultaneously assess multiple genes for inherited gene changes linked to elevated cancer risk. This is the primary cancer genetic test for prevention-focused individuals and those with a family history of cancer.
Panel testing has replaced older approaches that tested one gene at a time. A modern panel covers 25 to 80 genes (sometimes more) in a single test, giving a comprehensive view of hereditary cancer risk. The results apply to your lifetime risk and may be relevant for biological family members who could share the same inherited gene changes.
Cancer cell genomic sequencing, also called somatic testing of cancer tissue, analyzes the specific gene mutations present in a cancer. This test is done after a cancer diagnosis and is used to:
Cancer genomic sequencing analyzes DNA from the cancer itself. This may involve biopsy or surgical tissue from a solid tumor, or a blood or bone marrow sample in certain blood cancers. It is distinct from hereditary cancer testing. It tells you what mutations developed in the cancer cells, not what you inherited from your parents. Comprehensive tumor genomic panels can cover 300 to 600 or more genes within the tumor.
A liquid biopsy is a non-invasive blood test that detects fragments of tumor DNA, called circulating tumor DNA (ctDNA), released into the bloodstream by cancer cells. Although the term ctDNA includes the word “tumor,” liquid biopsy can also detect cancer-derived DNA from certain blood cancers, even when there is no solid tumor. It is used in several ways:
Liquid biopsy is a rapidly evolving field. Its clinical usefulness varies significantly by application, cancer type, and the specific test used. (NCI SEER Database)
Hereditary genetic cancer risk tests exist for a wide range of cancer types. The following cancers have the most well-established hereditary risk testing frameworks, with clinical guidelines supporting testing for eligible individuals.
Hereditary Breast and Ovarian Cancer syndrome, known as HBOC, caused primarily by BRCA1 and BRCA2 gene changes, is the most thoroughly studied hereditary cancer condition:
HBOC is 1 of 3 CDC Tier 1 Genomic Applications, meaning the scientific evidence for population-level genetic testing and acting on results is strong.
Lynch syndrome, caused by changes in mismatch repair genes including MLH1, MSH2, MSH6, and PMS2, as well as certain EPCAM deletions, is the most common hereditary colorectal cancer condition. It accounts for approximately 3 to 5% of all colorectal cancer cases, and carriers face a lifetime colorectal cancer risk of up to 80%.
Familial adenomatous polyposis (FAP), caused by APC gene changes, leads to nearly certain colorectal cancer development if untreated, with hundreds to thousands of polyps developing in the colon beginning in adolescence. MUTYH-associated polyposis (MAP) is a related condition with elevated colorectal cancer risk.
The CDC designates certain genomic conditions as Tier 1 (CDC, Tier 1 Genomic Applications), those with the strongest scientific evidence for population-level benefit from genetic testing.
The 2 cancer-related Tier 1 conditions are:
A Tier 1 designation means that, when mutations are identified, evidence-based clinical interventions are available, including enhanced surveillance, risk-reducing medications, and, in some cases, prophylactic procedures.
Hereditary cancer risk tests are appropriate for people who meet specific personal or family history or risk criteria. Here is a summary of when testing is clinically indicated.
Genetic testing is generally recommended when any of the following family history patterns are present:
If you have had a cancer diagnosis, you may qualify for hereditary cancer risk testing based on:
Not everyone who benefits from hereditary cancer risk testing has a dramatic family history. Many health-conscious, prevention-oriented people pursue testing to better understand their complete biological risk picture, even without a specific trigger.
Proactive hereditary cancer risk testing makes the most clinical sense for people who:
Your genetic information is private and protected, accessible only to you and your care team.
A positive result means a harmful inherited gene change was identified in one of the tested genes. This is an actionable finding. The specific gene involved helps determine which types of cancer are associated with increased risk and what the recommended clinical response should be. A positive result typically leads to:
A negative result means no harmful gene change was found in the tested genes. This substantially reduces the likelihood of a hereditary cancer syndrome, but it does not eliminate all cancer risk. Sporadic cancer, unrelated to inherited gene changes, can develop in anyone.
Some mutations may not yet be fully characterized in the scientific literature, and results from a panel that does not include all relevant genes should be interpreted carefully by a genetic counselor.
For people with a strong family history and a negative result, genetic counselors may still recommend surveillance based on the family pattern, even without a confirmed mutation.
A variant of uncertain significance, often called a VUS, is a DNA change identified during testing for which current science does not yet provide sufficient evidence to determine whether it is harmful or harmless. A VUS is not a positive result and should not be treated as one.
Not all laboratories report VUS findings. Some choose to report only results that are clinically actionable, meaning there is a clear next step. If your lab does not report VUS findings, your genetic counselor will focus only on results with a clear clinical meaning. Laboratories that do report VUS findings monitor the scientific literature, and some VUS results are eventually reclassified as harmful or harmless as evidence accumulates.
The most established path to hereditary cancer risk testing is through a physician referral, typically to a genetic counselor or genetics department at a hospital or cancer center. This pathway is often used when a specific family history concern has been raised during an appointment.
The limitation is that this pathway depends on a physician recognizing and raising a hereditary cancer risk concern.. Many routine appointments do not include proactive hereditary cancer risk discussions, and many people with meaningful family history are never offered testing through standard care.
Precision health management memberships provide coordinated access to hereditary cancer risk testing, genetic counseling, and clinical interpretation, without requiring that the process begin during a routine medical appointment. This works well for people who are proactively seeking testing or whose family history concerns have not been addressed through standard care.
Kadance members receive access to hereditary cancer risk testing covering 26 clinically actionable genes, including BRCA1, BRCA2, and the Lynch syndrome mismatch repair genes, through a CAP-accredited, CLIA-certified laboratory. Every gene was selected because a positive result leads to a concrete, evidence-based next step. Membership also includes genetic counseling to help interpret positive results and build a plan your physician can act on.
Some hereditary cancer risk tests are available online without going through a physician or genetic counselor. While they can be a starting point, there are a few important limitations to be aware of:
Coverage varies significantly by health plan, testing situation, and location. Testing is most likely to be covered when a physician has documented medical necessity based on family history or a personal cancer diagnosis. The Genetic Information Nondiscrimination Act, known as GINA, offers some federal protections against health insurers discriminating based on genetic test results, but it does not guarantee that testing costs will be covered.
Proactive testing without a current cancer diagnosis is less consistently covered. A genetic counselor can help clarify what is likely to be covered before testing begins.
A hereditary cancer risk test assesses risk. It is used for people who do not currently have the condition being assessed to determine whether an inherited gene change is present that elevates lifetime risk.
A genetic diagnostic test is done after a condition is suspected or confirmed, to characterize it. In cancer genetics, hereditary cancer panel testing is a risk-assessing tool. Tumor genomic sequencing performed after a cancer diagnosis is a diagnostic tool.
The distinction matters because hereditary cancer risk testing evaluates inherited risk and may be relevant both before and after a cancer diagnosis, while diagnostic testing is used to identify or characterize an existing condition.
Hereditary cancer risk tests from CAP-accredited, CLIA-certified laboratories detect pathogenic variants; they are designed to assess with analytical accuracy exceeding 99%. This means the test is very unlikely to miss a mutation that is present, or to report one that is not.
The more nuanced question of accuracy is whether a detected variant is correctly classified as harmful, harmless, or uncertain, which is why genetic counselor expertise in interpreting results is essential.
Hereditary cancer risk tests do not detect cancer. They identify inherited gene mutations that increase the risk of future cancer. They are preventive risk-assessment tools, not cancer detection tests.
Liquid biopsy and multi-cancer early detection tests are a different category that can detect signals suggesting cancer may currently be present, but they are distinct from hereditary risk testing and serve a different clinical purpose.
Hereditary cancer risk tests can give you information that standard healthcare rarely provides proactively: a biological picture of inherited cancer risk, based on the DNA that has been present in every cell of your body since birth. This is not speculative. It is genetic data interpreted against decades of clinical research on which gene changes cause which cancers and by how much.
For people who want to make better-informed decisions about how often to screen, which risk-reduction strategies apply to them, and which specialists to involve in their care, hereditary cancer risk testing provides the biological foundation that lifestyle habits and annual checkups alone cannot offer.
The 5 to 10% of people whose cancer risk is driven by an inherited gene change are, in most cases, not aware of it. Hereditary cancer risk tests change that.