Minimal Residual Disease
Also written as: MRD — Minimal Residual Disease
Small numbers of cancer cells that remain after treatment, detectable only through highly sensitive molecular or flow cytometric techniques.
Full Definition
Minimal residual disease (MRD) represents the presence of cancer cells below the detection threshold of conventional diagnostic methods but identifiable through sensitive techniques such as flow cytometry, PCR, or next-generation sequencing. MRD assessment is particularly important in hematologic malignancies like acute lymphoblastic leukemia and multiple myeloma, where its presence or absence strongly predicts treatment outcomes. The ability to detect one cancer cell among 10,000 to 1,000,000 normal cells has revolutionized treatment monitoring and risk stratification. MRD status often guides decisions about treatment intensification, maintenance therapy, or eligibility for clinical trials.
Usage
Usage note: Often abbreviated as MRD; when spelled out, 'minimal' is preferred over 'minimum' in clinical contexts.
In Context
- "Flow cytometry detected minimal residual disease at 0.01% of bone marrow cells after induction therapy." — Laboratory report
- "The patient achieved MRD-negative status after consolidation, indicating excellent prognosis." — Clinical summary