Analysis of discordant results in multi-technique platform-based MRD detection in multiple myeloma and the clinical...

The evaluation of measurable residual disease (MRD) in multiple myeloma now integrates multiple techniques, including next-generation flow cytometry (NGF), next-generation sequencing (NGS), PET/CT, and mass spectrometry. Discrepancies often arise due to differing sensitivities and methodologies - for instance, NGS (10^-6) detects lower disease levels than NGF (10^-5-10^-6). This can yield conflicting results, such as NGF negativity with NGS positivity, or discordance between bone marrow MRD and PET/CT findings. Such 'MRD paradox' demonstrates that heightened sensitivity may complicate clinical interpretation. Consequently, treatment decisions now require nuanced integration of multidimensional MRD data, beyond simple complete response. This review examines causes and implications of technical discordance and proposes an evidence-based integrative framework for MRD assessment to optimize individualized patient management.