Minimal Residual Disease (MRD) is an increasingly vital concept in cancer diagnosis, treatment monitoring, and prognosis, particularly for blood cancers like leukemia, lymphoma, and multiple myeloma. As treatment methods evolve, MRD detection has become a gold standard for evaluating how effective a cancer therapy is and whether a patient is at risk for relapse. This blog aims to help patients, caregivers, and healthcare professionals better understand what MRD is, why it matters, how it’s detected, and how it shapes modern cancer care strategies.
What Is Minimal Residual Disease (MRD)?
MRD refers to the small number of cancer cells that remain in a patient’s body after treatment, even when clinical tests show no signs of disease. These residual cancer cells can be undetectable by traditional imaging and blood tests but may later lead to a relapse if not identified and treated.
While the patient may appear to be in complete remission, molecular testing or advanced flow cytometry can reveal whether these hidden cancer cells persist (Healthline, 2022).
Why Is MRD Important?
Recognizing the value of MRD in guiding treatment and predicting outcomes leads us to the next key aspect, which is how these residual cancer cells are actually detected with accuracy and precision. Here’s how:
1. Prognostic Indicator
MRD status is one of the strongest predictors of patient outcomes. Studies show that MRD-negative patients (i.e., no detectable residual disease) often have a significantly lower risk of relapse and better long-term survival (Nature, 2024).
2. Guiding Treatment Decisions
By identifying whether cancer cells remain after treatment, MRD testing helps personalise therapy. For example:
- If MRD is positive, more aggressive or prolonged treatment may be needed.
- If MRD is negative, patients might be spared unnecessary side effects from further intensive therapies.
3. Early Relapse Detection
MRD testing can detect early molecular relapse before symptoms arise or before it shows up on imaging, offering a window for timely intervention.
How Is MRD Detected?
With these advanced detection methods in place, MRD testing plays a crucial role across different types of blood cancers. Let’s explore where and how MRD monitoring makes the most impact:
1. Flow Cytometry
This method identifies abnormal cells based on their surface markers. It’s fast and commonly used, but may not detect very low levels of disease.
2. Polymerase Chain Reaction (PCR)
PCR amplifies cancer-specific DNA sequences, allowing detection of one cancer cell among 100,000 normal cells.
3. Next-Generation Sequencing (NGS)
NGS offers even higher sensitivity, and it can identify one cancer cell among a million healthy cells, making it the most precise method currently available (Lymphoma.org).
MRD in Different Blood Cancers
Although MRD testing offers significant advantages, it’s important to understand the current challenges and limitations that may affect its use and interpretation. Here’s what you should know:
Leukemia
In acute lymphoblastic leukemia (ALL) and chronic lymphocytic leukemia (CLL), MRD negativity post-treatment correlates with longer remission periods and improved survival rates.
Lymphoma
MRD testing is especially useful in follicular and mantle cell lymphoma, helping guide post-remission strategies.
Multiple Myeloma
MRD negativity in multiple myeloma patients is now considered a key endpoint in clinical trials and treatment response. AI-driven analysis of clonal diversity is also being explored to enhance MRD interpretation (Nature, 2024).
MRD and Artificial Intelligence
Recent studies have explored how AI and machine learning can interpret complex MRD data. This includes analyzing clonal diversity and the variety of cancer cell mutations to predict how resistant a tumor might be to future treatments. In multiple myeloma, AI models show promise in identifying patterns linked with high relapse risk, even among MRD-negative patients (Nature, 2024).
MRD Status and Treatment Planning
| MRD Status | Treatment Implication |
| Negative | Consider de-escalation or maintenance therapy. |
| Positive | Intensify treatment or monitor closely for relapse. |
| Fluctuating | Evaluate clonal diversity and risk stratification. |
Challenges and Limitations
Despite these limitations, MRD continues to shape the future of cancer monitoring and personalised care. Let’s explore how this approach is redefining treatment decisions and improving outcomes:
- Standardization: MRD testing methods and interpretation vary across institutions.
- Cost and Access: High-sensitivity MRD tests like NGS may not be widely available or affordable.
- False Negatives: Even sensitive methods can miss MRD in cases of sample error or technical limitations.
Bottom Line
MRD enables precision oncology, allowing treatments tailored to microscopic disease levels. Whether you’re a clinician or patient, understanding MRD is key to long-term outcomes.
Stay One Step Ahead with MRD Testing
Early detection of Minimal Residual Disease (MRD) can prevent relapse and personalise your care. At Neeli Genetics, we combine flow cytometry, PCR, and NGS with expert guidance.
📅 Schedule Your MRD Assessment Today
FAQs
Can I still have cancer cells even if my scans look clear?
Yes. MRD refers to small numbers of cancer cells that may remain in your body even after treatment, despite normal results on imaging or standard blood tests. These cells can lead to relapse if not detected and addressed early.
How often should MRD testing be done?
The frequency of MRD testing depends on the type of cancer, treatment stage, and your oncologist’s recommendations. Typically, MRD is monitored at key points during and after treatment to assess remission status and relapse risk.
Is MRD testing only used for blood cancers?
Currently, MRD testing is most established in blood cancers like leukemia, lymphoma, and multiple myeloma. However, research is ongoing to explore its use in solid tumours, and new applications may emerge in the near future.
Which method of MRD detection is the most accurate?
Next-Generation Sequencing (NGS) offers the highest sensitivity, capable of detecting one cancer cell among a million healthy cells. However, the choice between NGS, PCR, or flow cytometry depends on the cancer type, available resources, and clinical need.
Can MRD status change over time?
Yes. MRD status is dynamic and can fluctuate. A patient may initially test MRD-negative but later become MRD-positive if residual cells begin to grow again. This is why regular monitoring is crucial for long-term cancer management.
Can I still have cancer cells if scans are clear?
Yes. MRD refers to residual cells undetectable by standard tests.
Is MRD testing only for blood cancers?
While established for blood cancers, research into solid tumors is ongoing (learn more).
Which MRD method is most accurate?
NGS offers the highest sensitivity.
FAQs
1. Can I still have cancer cells even if my scans look clear?
Yes. MRD refers to small numbers of cancer cells that remain in the body after treatment, which are undetectable through regular scans or blood tests but can lead to relapse if not identified early.
2. How often should MRD testing be done?
MRD testing is typically done at key milestones during and after cancer treatment. The frequency depends on your cancer type and your oncologist’s recommendations for monitoring remission and relapse risk.
3. Is MRD testing only used for blood cancers?
MRD testing is most commonly used for blood cancers like leukemia, lymphoma, and multiple myeloma. However, research is ongoing to expand its application to solid tumours in the near future.
4. Which MRD detection method is the most accurate?
Next-Generation Sequencing (NGS) is currently the most sensitive MRD detection method, capable of identifying a single cancer cell among one million healthy cells.
5. Can MRD status change over time?
Yes. MRD is dynamic. A patient may test negative shortly after treatment and later test positive again. Regular monitoring helps detect relapse early and guide timely treatment decisions.
References
Thomas, T. H., Srakocic, S. Minimal Residual Disease. Healthline, 2022. https://www.healthline.com/health/minimal-residual-disease
Lymphoma Research Foundation. Ask the Doctor: What is Minimal Residual Disease (MRD)? https://lymphoma.org/news/ask-the-doctor-what-is-minimal-residual-disease-mrd
E. S. et al. Measurable Residual Disease Dynamics in Multiple Myeloma and the Influence of Clonal Diversity Analyzed by Artificial Intelligence. Blood Cancer Journal, Nature, 2024. https://www.nature.com/articles/s41408-024-01102-x
