What is Minimal Residual Disease (MRD)

Minimal Residual Disease (MRD) refers to the tiny traces of cancer cells that may remain in a patient’s body even after treatment has achieved a complete response (CR) in diseases like multiple myeloma (MM).

These lingering cancer cells, often present at very low levels, are of utmost concern in cancer care.

Detecting and quantifying MRD has become a critical aspect of patient management, impacting treatment decisions and prognostic evaluations.

Minimal Residual Disease (MRD) Assessment in Patient Care

Assessing MRD is a pivotal component of modern oncology, providing valuable insights into a patient’s disease status.

Here, we delve into the significance of MRD assessment in patient care.

• The Challenge of MRD Persistence: Despite achieving CR, many MM patients experience disease progression or relapse. This can be attributed to the persistence of MRD. These residual cancer cells, although often undetectable by conventional methods, can serve as a breeding ground for disease recurrence.

• Advanced Techniques for MRD Assessment: To address this challenge, advanced techniques have been developed. Multiparameter flow cytometry (MFC), allele-specific oligonucleotide PCR, and high-throughput sequencing (NGS) are three high-sensitivity methods used to quantify MRD in MM. These techniques are instrumental in detecting even subclinical levels of MRD, providing crucial prognostic information.

• NGS, A Game-Changer: Notably, NGS of immunoglobulin (IG) rearranged genes has emerged as a powerful tool in MRD assessment. With a sensitivity of at least 0.001%, NGS can identify and quantify pathological clonal cells effectively. Although it may require centralized laboratories, NGS technology holds immense promise.

• Our Simplified Approach: In our ongoing efforts to enhance MRD assessment, we’ve developed an in-house deep-sequencing method. This method employs standardized primers to amplify IG sequences and can be performed using small DNA samples. Libraries are created through adaptor oligo ligation and sequenced using state-of-the-art platforms.

• Robust Analytical Validity: Our approach demonstrates a high degree of specificity and sensitivity. Clonotypes, indicative of MRD, are identified with precision. Importantly, this method shows excellent analytical sensitivity and reproducibility, making it a valuable tool in MRD quantification.

• Clinical Implications: Our findings suggest that achieving MRD negativity, as determined by our deep-sequencing method, correlates with improved progression-free survival (PFS) and overall survival (OS) in MM patients. Prolonged treatment regimens, such as those involving 18 cycles, show promise in increasing the rate of molecular responses and enhancing patient outcomes.

• Comparison with Other Methods: Our method’s performance is comparable to traditional techniques like MFC, while offering the benefits of increased sensitivity and automation. Patients with discordant results between our method and MFC show intermediate survival, underlining the importance of precise MRD assessment.

• New Response Criteria: The International Myeloma Working Group (IMWG) has recognized the need for new response criteria that account for deeper responses, including sequencing MRD negativity. Our deep-sequencing method aligns with these criteria, potentially contributing to more accurate disease monitoring.

Incorporating Valuable Links

For more detailed information on MRD assessment techniques, you can visit Altum Sequencing, a company that works with liquid biopsy, which is non-invasive, rapid, accurate, and repeatable.

To explore the official definition of MRD in the context of cancer terminology, refer to Cancer.gov’s MRD Definition.

If you would like to learn more about MRD, check this case study.

In conclusion, MRD assessment has revolutionized cancer care by providing a deeper understanding of disease status and prognosis.

Our in-house deep-sequencing method is at the forefront of these advancements, offering hope for improved outcomes in patients.