Did you know your DNA can reveal powerful clues that help doctors choose the best treatments for your body and your condition? This is the core of genomic testing, one of the newest tools in personalized health care.

Genomic testing isn’t just for scientists or people with rare conditions. It’s part of a growing movement in medicine known as precision health, which uses a person’s unique genetic makeup to help clinicians make better decisions. For older adults, this can mean earlier detection of certain chronic diseases, more effective treatments, and fewer unwanted side effects.

Below, we walk you through what genomic testing is, how it works, and how it can support your health and well-being as you age.

What is genomic testing?

Genomic testing examines many or all of a person’s genes to understand how they affect their health, disease risk, or treatment response. Tests are usually done with a sample of blood, saliva, or tissue (e.g., from a tumor). Once this sample is analyzed in a lab, the results can help identify risks for certain diseases and inform treatment choices. They may even shed light on why a medication didn’t work as expected.

There are several types of genomic testing:

• Diagnostic testing: This genomic test might be ordered if your physician suspects you have a certain genetic condition based on your symptoms. It looks for specific gene variants known to be associated with that illness.
• Predictive testing: Clinical genetic testing has long been a tool for determining disease risk. Now, genomic testing is also being used to predict the likelihood of illness before a person shows any signs. Your doctor may order predictive genomic testing if you have one or more close family members with a certain genetic condition, since that increases your risk of developing the same condition.
• Pharmacogenomic testing: With this variety of genomic testing, lab technicians analyze your DNA for gene changes that impact the way your body breaks down, absorbs, and utilizes medications.
• Tumor genomic testing: For people diagnosed with cancer, genomic testing of tumor cells for certain gene or protein changes (called biomarkers) can tell clinicians how the cancer grows and how fast it’s likely to progress. It can also yield clues as to how successful certain treatments will be, allowing oncologists to better target therapies and avoid wasting time with trial and error.

How is genomic testing used in precision health?

Precision health focuses on proactive and personalized care. Rather than relying on general medical guidelines, this approach tailors care based on your genetics, lifestyle, environment (e.g., housing conditions, exposure to toxins), and health and family history.

Genomic testing is a key part of precision health. Here are a few ways it’s being used:

Cancer care

Genomic testing can find inherited mutations that raise your risk for certain cancers, such as breast or colon cancer. If you have cancer, it can help your care team choose the most effective treatments based on how your tumor behaves.

Genomic tumor testing is used with common cancers (e.g., breast cancer) as well as rare cancers like thyroid cancer and metastatic melanoma. One study investigated whether patients with advanced non-small cell lung cancer could receive more targeted treatment after standard therapy. Genomic testing was performed on biopsy samples taken at diagnosis, and again when the cancer progressed. The researchers found that 85% of patients' cancer cells showed specific genetic or molecular changes that could be targeted with available therapies.¹

Another study discovered a 33% lower risk of mortality when treatment plans for advanced cancers were precisely matched with a patient’s genomic profile.²

Medication safety and efficacy

Through pharmacogenomic testing, doctors can predict how your body may react to specific medications. This can help prevent unpleasant side effects and improve the effectiveness of treatments. Pharmacogenomic testing can also reveal which treatments are likely to work best with the fewest side effects. It’s currently being used to evaluate the response to medications that treat certain cancers, HIV, heart disease, and depression.

Chronic conditions

Some genomic tests can identify whether you have a higher risk of chronic diseases like heart disease, high cholesterol, and type 2 diabetes. Knowing this earlier may help you and your doctor take steps to reduce your risk.

How is genomic testing different from genetic testing?

The terms genomic testing and genetic testing are often used interchangeably, but they aren’t quite the same:

• Genetic testing looks at your DNA to identify changes or mutations in specific genes. These changes can help determine whether you have, are at risk for, or could pass on certain health conditions. For example: Marcus has a family history of high cholesterol. He gets genetic testing and is found to have familial hypercholesterolemia (FH), an inherited condition that raises his risk for early heart disease. With this result, Marcus’ doctor recommends lifestyle changes and early treatment to lower his cholesterol.
• Genomic testing looks at many genes—or sometimes all of your genes—at once. It gives a broader picture of how your genes work together and how they may influence your overall health or your body’s response to certain treatments. Some genomic tests have predictive value, identifying whether you’re at increased risk for certain diseases. But, unlike genetic testing, genomic testing is also used on cancer cells to gain insights that may influence treatment decisions.

What is genetic counseling?

If you’re considering genomic or genetic testing, you may be referred to a genetic counselor. These are trained health professionals who help people understand what their genes may say about their health.

You might meet with a genetic counselor before or after your test, or both. They can:

• Help you decide whether genomic testing is right for you
• Explain what the results mean and what next steps to take
• Offer support for difficult decisions, especially if a risk is found

They can also help you consider how your test results might affect your family. For instance, if you test positive for a genetic trait that increases your risk for cancer, your close family members may want to get tested, too.

What to know when considering genomic testing

While genomic testing can offer many benefits, it’s not the right choice for everyone. Here are a few things to know:

• It may not apply to every condition: Not all health problems are tied to genes. This means genomic testing may not provide all the answers needed to understand or manage a disease.
• The results could be upsetting: It’s natural to feel anxious, sad, guilty, or overwhelmed about genomic testing—especially if the results are not favorable.
• You may have privacy concerns: Your genetic data is personal and highly sensitive. Don’t be afraid to ask how your data will be used, stored, and shared.
• It might not be covered by insurance: Some genomic and genetic tests are expensive and may not be covered by Medicare or private health plans. Before you agree to any testing, be sure to check your plan’s coverage and find out what, if any, precision health tests are covered. If there is no coverage, ask what your out-of-pocket costs will be to avoid unwelcome surprises later on.

Insights that lead to healthier aging

By offering a window into our DNA, genomic testing opens the door to improved disease prevention, earlier detection and diagnosis, and more successful treatment paths. If you’re curious about whether it’s right for you, talk to a trusted health care professional. Genomic testing and precision health may not fit into everyone’s care plan—but for some older adults, they can be valuable tools that support a long and vibrant life.

Sources

1. Malene Støchkel Frank, et al. Actionable Molecular Alterations Are Revealed in Majority of Advanced Non-Small Cell Lung Cancer Patients by Genomic Tumor Profiling at Progression after First Line Treatment. Cancers. December 28, 2021. Found on the internet at https://pmc.ncbi.nlm.nih.gov/articles/PMC8749927/

2. Christophe Massard, et al. High-Throughput Genomics and Clinical Outcome in Hard-to-Treat Advanced Cancers: Results of the MOSCATO 01 Trial. Cancer Discovery. June 1, 2017. Found on the internet at https://aacrjournals.org/cancerdiscovery/article/7/6/586/5997/High-Throughput-Genomics-and-Clinical-Outcome-in