A Comparison of Different Staging Systems for Multiple Myeloma: Can the MRI Pattern Play a Prognostic Role?

Abstract

The objective of this study is to compare the most recent systems for the staging of multiple myeloma (MM), the Durie-Salmon PLUS system and the International Staging System, according to patients' survival rates and response to therapy. Another objective is to verify whether patterns of bone marrow alteration on MRI (i.e., focal, diffuse, or variegated patterns) can provide prognostic information for patients with MM. We retrospectively enrolled 85 patients with MM who were monitored for a minimum of 6 years and who underwent contrast-enhanced spinal and pelvic MRI at 1.5 T and whole-body FDG PET/CT at the time of diagnosis. Patients underwent MM staging performed using both staging systems and were divided into groups on the basis of their MRI patterns. These patient groups were then compared in terms of survival, response to therapy, and duration of response. Both staging systems showed great capability in differentiating patients with a worse prognosis from patients with a better outcome, with the capability of both systems found to be statistically significant, albeit less statistically significant for the Durie-Salmon PLUS system (p = 0.010 vs p = 0.046, respectively). Patients with a focal pattern on MRI had a worse survival rate than did the patients with other MRI patterns (p = 0.032). These data indicate that both the International Staging System and the Durie-Salmon PLUS system have great potential for characterizing and stratifying MM to determine the survival outcome and therapy response of patients. Observation of a focal pattern on MRI seems to be associated with poorer survival.