Leukemia Biomarker Testing
Biomarker tests look at specific proteins, genes, and other substances that give doctors information about cancer. They are an important component of personalizing cancer treatment, which is also referred to as precision medicine. Other names for biomarker tests include genomic tests, tumor genetic tests, and molecular tests.
Biomarker tests vs. genetic tests
You may hear some people use the term “genetic tests” when discussing biomarker tests. But biomarker tests are different from genetic tests. Genetic tests are done to find out more about your family health traits.
Biomarker tests evaluate genes and other substances related to cancer. They help doctors make a diagnosis and predict how the disease may behave or respond to certain treatments. Genetic tests typically look for present-at-birth gene mutations (changes) that you’ve inherited from your parents.
How do biomarker tests help with leukemia treatment?
Biomarker tests can give your doctor information about what treatments may work for your specific leukemia. They can also indicate if you are resistant to certain treatments. They may help with:
- Determining the expected course of the disease
- Evaluating the effectiveness of a treatment
- Detecting cancer that remains after you’ve finished treatment (minimal residual disease)
- Identifying how the disease has changed. Repeating biomarker testing is considered standard of care if you experience disease relapse. Doctors repeat the tests because mutations may be different than when you first received a diagnosis.
Biomarker tests can help diagnose cancer and guide cancer treatment. They are an important part of precision medicine, an approach that tailors your treatment plan to the specific characteristics of your condition.
Types of biomarker tests for leukemia
Doctors often use samples from blood tests or bone marrow tests to look for biomarkers. Common types of biomarker tests include:
Karyotype
A karyotype looks at your chromosomes, the structures that contain your genetic code (deoxyribonucleic acid, commonly called DNA) and proteins. The test looks at the size, shape, and number of chromosomes in a cell sample. Typical cells have 23 pairs of chromosomes, totaling 46 in all.
A karyotype may show irregularities in your chromosomes, such as broken, missing, or extra parts. It could also be a chromosome that has moved (translocated) out of its typical position.
Fluorescence in situ hybridization (FISH)
FISH tests look at the DNA sequences or genes on your chromosomes. Doctors add a fluorescent dye to parts of your DNA. Then they combine the DNA with tissues or cells and view the samples under a special microscope. The dye causes your DNA to light up when it binds to certain genes or chromosomes.
The test allows doctors to identify irregularities in your chromosomes. It looks for changes that are too small to see with other tests, such as overlapping, deletion, or translocation of DNA pieces.
Immunohistochemistry
Immunohistochemistry tests look for specific substances (antigens) in a tissue sample. It uses antibodies, proteins that bind to specific antigens. Doctors may use immunohistochemistry to identify the cancer type and predict treatment response.
Next-generation sequencing
Next-generation sequencing (NGS) looks at sections of DNA or ribonucleic acid (RNA), the substance that carries instructions from your DNA. It shows gene changes (mutations) or other variations in your DNA.
Doctors often use NGS to choose targeted therapy. Targeted therapies look for and target specific cell changes or proteins that cause leukemia.
Polymerase chain reaction
A polymerase chain reaction (PCR) is a technique that multiplies your DNA or RNA to study it. It can find very small concentrations of cancer cells before they are visible on a microscope.
Doctors commonly use PCR after treatment. They use it to look for any remaining cancer (measurable residual disease) or for signs of cancer returning (recurrence).
Helpful resources
Support can make a big difference when facing a leukemia diagnosis. Connect with others through our peer support programs or browse our directory of resources for patients, families, and caregivers.
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