What is a minimal residual disease (MRD)

1. What is a minimal residual disease (MRD)? After finishing a course of therapy, few words sound more useful to a patient than “complete remission.” It’s an expression that the therapy has worked, and there is no proof of cancer based on scans or lab trials. However, there is a separate phrase that can be rather confusing to patients — minimal residual disease (MRD). This term is used often by doctors when treating

2. patients with blood cancers, such as leukemia, lymphoma, or multiple myeloma. MRD guides cancer cells to remain behind medication that can’t be seen by those same scans or tests. But what exactly does it mean for patients? How do you describe the minimal residual disease to patients? A minimal residual disease is a small digit of cancer cells left in the body behind therapy. These cells can reach back and cause damage in our patients. for instance, we look for a response after chemotherapy treatment by looking under the microscope for cancer cells current in a bone marrow biopsy. When there are no cancer cells present, and the bone marrow is making normal cells, we call that a full response.

3. However, we know that if we don’t do further treatment, a portion of these patients will experience a relapse. That suggests some leukemia cells were suppressing that we weren’t able to catch under the microscope. That is a minimal residual disease, or perhaps a more useful term is a measurable residual disease. Typically, these cells don’t cause any symptoms, but they have the potential to guide to a regression.

4. If we can’t catch minimal residual disease under the microscope, how do we test for it? We now have much more sensitive assays available to us that allow us to quantify MRD. These could include next-generation genetic sequencing, where we can analyze bone marrow samples for genetic mutations. If there are mutations present, that means there is a minimal residual disease, even though we can’t see anything under the microscope. HeamPath can also use a method called flow cytometry, which allows us to look in the same models for abnormal proteins on the surface of cells. By determining how many cells have irregular proteins detected, we can get a better sense of residual cancer cells. Using these new assays, we routinely try to quantify whether a patient has MRD following standard therapy.