Evaluation of the Prognostic Value of the Mayo Additive Staging System and Minimal Residual Disease in Newly Diagnosed Multiple Myeloma Patients

Introduction: This study aimed to evaluate the prognostic value of the Mayo additive staging system (MASS) and minimal residual disease (MRD) in newly diagnosed multiple myeloma (NDMM) patients.

Methods: A total of 238 NDMM patients were enrolled in Beijing Chaoyang Hospital. Fluorescence in-situ hybridization and next-generation flow cytometry were used to examine cytogenetic abnormalities and MRD, respectively. The patients were classified into three groups to compare the effects on progression-free survival (PFS). Univariate and multivariate analyses were applied to identify the survival-related factors.

Results: For MASS group, the PFS was significant difference in MASS I, II, and III patients (p = 0.0006); the patients with sustained MRD-negative, non-sustained MRD-negative, sustained MRD-positive, and non-sustained MRD-positive were divided into Groups 1, 2, 3, and 4, respectively. The Group 1 patients had superior PFS than Groups 2 and 3 patients (p < 0.05), but no difference in PFS was observed for Group 2 versus Group 3, Group 2 versus Group 4, and Group 3 versus Group 4 patients. For the MASS and MRD groups, among Groups 2, 3, and 4, MASS I patients had a superior PFS, while III patients showed the opposite result. Strikingly, no difference in PFS for Group 1 patients regardless of the MASS stage was observed. Despite being in MASS II and III, the PFS of Group 1 patients was longer than those with the other three groups. Response to treatment was an independent prognostic factor for MM patients.

Conclusion: Patients with an accumulation of high-risk factors and MRD-positive have poor outcomes. Sustained MRD-negative may improve high-risk patients' prognoses.