A retrospective, multicenter analysis of multiple myeloma patients with extramedullary disease in the real-world provided insight into how the demographic and clinical characteristics of this patient population impact treatment outcomes. The study findings were recently published in Haematologica.
The study included 226 myeloma patients with extramedullary plasmacytoma or paraosseous involvement for whom extramedullary disease was detected at the time of diagnosis or at relapse between January 2010 and November 2017.
Among the 130 patients with extramedullary disease detected at diagnosis, 92 had extramedullary plasmacytoma and 38 had paraosseous involvement. Among the 96 patients with extramedullary disease detected at relapse, 84 had extramedullary plasmacytoma and 12 had paraosseous involvement.
The analysis revealed several observations suggesting better outcomes for patients with paraosseous involvement. For example, a higher complete response rate was seen among patients with paraosseous involvement at diagnosis (34.2% vs 19.3%, respectively), which lacked statistical significance, and relapse (54.5% vs 9%, respectively; P =.001) compared with patients with extramedullary plasmacytoma. Patients with paraosseous involvement at diagnosis also had longer overall survival (OS) compared with extramedullary plasmacytoma (not reached vs 46.5 months, respectively).
The timing of extramedullary disease was also important. For instance, patients with paraosseous involvement had longer progression-free survival (PFS) if the disease presented at diagnosis as compared with presentation at relapse (51.7 vs 38.9 months, respectively).
In addition, a multivariate analysis revealed several factors that were independently associated with longer OS, including paraosseous involvement, extramedullary disease at diagnosis, International Staging System I, and receipt of autologous stem cell transplantation.
“Given the dismal outcome of EMD reported by others and us there is an unmet need to improve PFS and OS,” the study authors wrote. Despite the limitations of a retrospective approach, they wrote, “the response kinetics reported in our real-world study may provide guidance in designing future EMD clinical trials.”
Beksac M, Cengiz Seval G, Kanellias N, et al. A real world multicenter retrospective study on extramedullary disease from Balkan Myeloma Study Group and Barcelona University: analysis of parameters that improve outcome [published online July 5, 2019]. Haematologica. doi: 10.3324/haematol.2019.219295