More and more cancer patients are hearing about genomic tumor testing. But what does it actually mean, and how can it help?
Modern oncology is evolving rapidly. While cancer treatment was once selected primarily based on where the cancer originated—such as the lung, breast, or colon—today, increasing attention is being given to the unique genetic characteristics of each patient’s tumor.
This is why genomic tumor testing has become an important part of precision oncology. By analyzing the molecular profile of a tumor, these tests can provide physicians with valuable information that may help guide more personalized treatment decisions.
What Is Genomic Tumor Testing?
Genomic tumor testing is a comprehensive laboratory analysis that examines the DNA of cancer cells and, in some cases, their RNA.
The purpose of the test is to identify genetic alterations within the tumor that may be clinically relevant when considering treatment options.
It is important to understand that this test is not designed to determine whether a person has inherited an increased risk of developing cancer. Instead, it analyzes genetic changes that have developed specifically within the tumor itself.
What Is the Difference Between Genetic and Genomic Testing?
Although these terms are often used interchangeably, they refer to different types of testing.
Inherited genetic testing examines genes passed down from parents and can identify hereditary cancer risk associated with certain inherited mutations.
Genomic tumor testing, on the other hand, analyzes genetic alterations that have developed in cancer cells over time. These tumor-specific changes may provide important information about the biology of the disease and help inform treatment decisions.
Why Is Tumor Genetics Important?
Even when two patients are diagnosed with the same type of cancer—for example, lung cancer—their tumors may be genetically very different.
One tumor may contain a mutation for which a targeted therapy is available, while another may have an entirely different molecular profile.
For this reason, the same treatment is not necessarily appropriate for every patient.
Genomic tumor testing provides physicians with additional insight into the molecular characteristics of a tumor, which can be an important factor in treatment planning.
When Might a Physician Recommend Genomic Testing?
The decision to perform genomic testing is always made by the treating physician based on the individual clinical situation.
Genomic tumor testing may be considered when:
- advanced or metastatic cancer has been diagnosed;
- targeted therapy options are being evaluated;
- participation in a clinical trial is being considered;
- standard treatment options are limited; or
- additional molecular information is needed to support clinical decision-making.
Every patient’s situation is unique, and the potential benefits of testing should always be discussed with the treating physician.
How Is Genomic Tumor Testing Performed?
In most cases, testing is performed using tumor tissue that has already been collected during a biopsy or surgery.
In certain situations, genomic testing may also be performed using a blood sample—a method commonly known as a liquid biopsy—if the treating physician considers it appropriate.
The sample is then sent to a specialized laboratory, where comprehensive molecular analysis is performed.
What Can the Test Results Show?
Depending on the type of genomic test performed, the report may include information about:
- clinically relevant genetic alterations;
- molecular characteristics of the tumor;
- predictive and prognostic biomarkers;
- potential treatment strategies; and
- possible eligibility for clinical trials, when included in the scope of the specific test.
The results should always be interpreted by the treating physician in the context of the patient’s overall clinical condition.
Does Genomic Testing Guarantee That a Suitable Treatment Will Be Found?
Not necessarily.
It is important to understand that genomic tumor testing does not guarantee that an actionable genetic alteration or a specific treatment option will be identified.
However, it may provide additional molecular information that helps physicians make more informed decisions about the next steps in a patient’s treatment plan.
When Should You Talk to Your Doctor About Genomic Testing?
If you have been diagnosed with cancer and would like to learn more about advanced diagnostic options, it is worth discussing genomic tumor testing with your treating physician.
Every patient’s case is different, and only your healthcare provider can determine whether genomic testing may be appropriate for your specific situation.