Comparative Prognostic Value of the Durie–Salmon, ISS, and mSMART Staging Systems in Multiple Myeloma

Objectives: Multiple myeloma (MM) is a plasma cell malignancy characterized by marked interpatient variability in clinical course and prognosis. Accurate staging systems are essential for risk stratification and survival prediction. We aimed to compare the prognostic performance of the Durie–Salmon (DS), International Staging System (ISS), and Mayo Stratification of Myeloma and Risk-Adapted Therapy (mSMART) systems in predicting overall survival.
Methods: This retrospective study included 110 patients diagnosed with MM at a tertiary hematology center. Patients were staged according to the DS, ISS, and mSMART systems. Overall survival (OS) was evaluated using the Kaplan–Meier method, and prognostic factors were evaluated using univariate and multivariate Cox regression analyses.
Results: Advanced disease stages were significantly associated with poorer overall survival across all staging systems (Durie–Salmon, p<0.001; ISS, p=0.007; mSMART, p=0.001). Among the evaluated models, only DS stage IIIB remained an independent predictor of mortality in multivariate analysis (HR=11.55, 95% CI=3.29–40.56, p < 0.001). ISS stage and mSMART risk categories did not retain independent prognostic significance after adjustment.
Conclusion: The DS staging system showed the strongest association with overall survival among the evaluated mod-els. Although biologically based risk stratification has advanced considerably, traditional clinical staging systems still provide valuable and practical guidance in routine clinical practice.

Keywords: Durie–Salmon; ISS, Multiple myeloma, mSMART, prognosis