Evidence for the Monitoring of Minimal Residual Disease Dynamics to Guide Clinical Practice in Patients with Multiple Myeloma.

Multiple myeloma (MM) is a heterogeneous cancer that remains incurable. After treatment, the presence of residual myeloma clonal cells, or minimal residual disease (MRD), leads to tumor recurrence (relapse) and treatment failure (refractory disease). Strong clinical evidence indicates MRD is a surrogate marker of survival in patients with MM and is of important prognostic value in disease management. MRD status is dynamic and longitudinal changes in MRD status have different clinical implications. For example, sustained MRD negativity (undetectable MRD) has been associated with greatly improved survival outcomes, whereas the loss of MRD negativity is associated with disease progression. Although research on the prognostic impact of MRD dynamics in real world clinical practice is ongoing, several major concerns remain to be addressed before implementing the monitoring of MRD dynamics and MRD-guided therapeutic decision making in everyday clinical practice in the management of MM. In this review, we discuss the prognostic and clinical value of MRD dynamics, the evidence from literature for MRD-guided clinical decision making, and the challenges around implementing monitoring of MRD dynamics into clinical practice.