Minimal Residual Disease in Myeloma in 2024: Where We are Today

Minimal residual disease (MRD) refers to a small population of cancer cells that persists in the body after treatment. Often undetectable using traditional diagnostic methods, these cells can eventually cause relapse in patients who appear to have achieved a complete response (CR) to treatment. For that reason, MRD has become a vital parameter in evaluating the effectiveness of cancer therapies, particularly in hematological malignancies, such as multiple myeloma (MM), and certain solid tumours. Detection of MRD represents a challenge, as the disease may not cause symptoms or be detected through traditional methods (i.e., visible under a microscope). Nevertheless, these cells are often responsible for disease relapse; alternatively, sustained absence of these cells may portend a prolonged remission and presumably be required for disease cure. Therefore, monitoring and detecting MRD are increasingly recognized as essential for long-term patient care and treatment planning.