Minimal Residual Disease (MRD) & Disease Monitoring

Causes & Risk Factors

MRD testing is considered at specific points in a treatment and monitoring pathway, rather than being prompted by risk factors:

•  Following induction or consolidation treatment for certain leukemias, to assess depth of response

•  As part of scheduled monitoring during and after treatment for selected hematological malignancies

•  When assessing whether a patient remains in remission or whether disease is beginning to reappear

•  To help guide decisions about treatment duration, intensity, or the need for additional therapy

Symptoms & When to Test

MRD testing is a monitoring tool used in patients with a known, previously diagnosed hematological malignancy — it is not driven by new symptoms, though the disease itself may cause symptoms if MRD progresses to overt relapse.

•  Performed as scheduled monitoring in patients with known hematological malignancy under treatment or in remission

•  Not typically used as a first-line diagnostic test in a person without a prior diagnosis

•  A rising MRD level, without necessarily causing symptoms, may prompt closer monitoring or treatment adjustment by your hematologist

When Should You Consider Testing?

MRD testing timing is determined by your treating hematologist as part of your specific treatment protocol and monitoring schedule, typically at defined milestones during and after treatment for the relevant hematological malignancy.

Why Tests Are Combined

Different MRD techniques offer different sensitivity and are suited to different diseases — flow cytometry identifies residual abnormal cells based on their surface marker profile, while molecular and PCR-based methods can detect residual disease at a much lower level by identifying specific genetic markers unique to the patient's original malignancy.

The choice of technique depends on the specific hematological malignancy and what genetic or immunophenotypic marker was identified at original diagnosis — MRD testing generally requires that a trackable marker was established at diagnosis, which is one reason thorough initial diagnostic testing (including flow cytometry and molecular studies) matters beyond just confirming the diagnosis.

Because MRD testing is far more sensitive than routine blood counts or bone marrow morphology, it can detect very low levels of residual disease that would otherwise go unnoticed — informing treatment decisions earlier than would otherwise be possible.

Tests Available at NPL

Most tumor molecular tests, histopathology, IHC, and genetic tests do not require fasting. However, some blood-based investigations ordered alongside cancer testing may have specific preparation requirements. Please follow the instructions provided by your doctor or NPL.

Home Sample Collection

MRD testing from peripheral blood can, for some hematological malignancies, be arranged through NPL's standard home sample collection service — confirm with your treating hematologist whether blood-based MRD monitoring applies to your specific disease.

For diseases where MRD assessment requires a bone marrow sample, this must be obtained by a hematologist at a hospital or clinic — this is not a home collection service.

Once your sample (blood or marrow) is obtained, NPL processes MRD testing at our accredited laboratory using the technique appropriate to your original diagnostic markers.

Reports are delivered securely to your treating hematologist, and to you, within the timeframe specified for the test ordered.

When to See a Doctor

•  MRD monitoring is scheduled by your treating hematologist as part of your treatment protocol — attend all scheduled monitoring visits

•  Contact your hematologist promptly if you develop new symptoms suggestive of disease relapse between scheduled monitoring visits