Minimal Residual Disease Testing’s Variability Across Cancer Types

Testing for minimal residual disease (MRD) testing, also called measurable residual disease, is primarily used for blood cancers such as lymphoma and leukemia, according to the National Cancer Institute.

Dr. Christopher R. Flowers explained that MRD can have different meanings depending on the type of cancer, with no single interpretation. However, it often refers to cases where a patient, after completing treatment, undergoes standard evaluations such as CT scans or blood tests, which show no detectable disease. Despite these negative results, the patient then undergoes a blood-based test for MRD, defined by the National Cancer Institute as a small number of cancer cells that remain in the body during or after treatment.

In an interview with CURE®, Flowers, a researcher in the Department of Lymphoma-Myeloma at The University of Texas MD Anderson Cancer Center in Houston, discussed how MRD testing varies across different cancer types. He explained its significance in monitoring disease progression, assessing recurrence risk and interpreting results based on the unique characteristics of each cancer.

Transcript:

For different diseases, that can be a different kind of test, so that could be things like flow cytometry that is able to detect, to a very small level, circulating cells from cancer. It could be a test like a genomic test or genetic test, where it can detect evidence of the genes that are associated with that cancer even though you can't detect levels of that cancer itself that are circulating in the bloodstream. That result can mean that there is some likelihood of the cancer coming back at a later date related to that test being positive.

There is the possibility, in some settings, of that being a false positive test, so that's something that's also important to keep in mind; the test could come back positive, but there really is not detectable cancer in that setting. That's much less common for these kinds of tests, but that still can occur. For different cancers, the detection of minimal residual disease means different things. For some cancers that might be more rapidly growing, that may be a sign that the cancer is coming back in a relatively short period of time. For other kinds of cancers that may be slower growing, it may mean that there's a need for continuing monitoring over time.

Transcript was edited for clarity and conciseness.

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