Minimal Residual Disease Assessment in the Context of Multiple Myeloma Treatment

With contemporary therapeutic strategies in multiple myeloma, heretofore unseen depth and rate of responses are being achieved. These strategies have paralleled improvements in outcome of multiple myeloma patients. The integration of the next generation of proteasome inhibitors and antibody therapeutics promise continued improvements in therapy with the expectation of consistent depth of response not quantifiable by current clinical methods. As such, there is a growing need to develop adequate tools to evaluate deeper disease response after therapy and to refine the response criteria including the minimal residual disease. Several emerging techniques are being evaluated for these purposes including multi-parameter flow cytometry, allele-specific oligonucleotide polymerase chain reaction, next-generation sequencing, and imaging modalities. In this review, we highlight the recent developments and evaluate advantages and limitations of the current technologies to assess minimal residual disease. We also discuss future applications of these methodologies in potentially guiding multiple myeloma treatment decisions.