New criteria to identify risk of progression in monoclonal gammopathy of uncertain significance and smoldering multiple myeloma based on multiparameter flow cytometry analysis of bone marrow plasma cells

• Published in: Blood Vol. 110; no. 7; pp. 2586 - 2592
• Main Authors: Pérez-Persona, Ernesto, Vidriales, María-Belén, Mateo, Gema, García-Sanz, Ramón, Mateos, Maria-Victoria, de Coca, Alfonso García, Galende, Josefina, Martín-Nuñez, Guillermo, Alonso, José M., de las Heras, Natalia, Hernández, José M., Martín, Alejandro, López-Berges, Consuelo, Orfao, Alberto, San Miguel, Jesús F.
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.10.2007
• Subjects: Adult; Aged; Aged, 80 and over; Bone Marrow Cells - pathology; Disease Progression; Female; Flow Cytometry; Humans; Male; Middle Aged; Multiple Myeloma - classification; Multiple Myeloma - complications; Multiple Myeloma - epidemiology; Multiple Myeloma - pathology; Paraproteinemias - classification; Paraproteinemias - complications; Paraproteinemias - epidemiology; Paraproteinemias - pathology; Phenotype; Plasma Cells - pathology; Risk Factors
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2007-05-088443

Monoclonal gammopathy of uncertain significance (MGUS) and smoldering multiple myeloma (SMM) are plasma cell disorders with a risk of progression of approximately 1% and 10% per year, respectively. We have previously shown that the proportion of bone marrow (BM) aberrant plasma cells (aPCs) within the BMPC compartment (aPC/BMPC) as assessed by flow cytometry (FC) contributes to differential diagnosis between MGUS and multiple myloma (MM). The goal of the present study was to investigate this parameter as a marker for risk of progression in MGUS (n = 407) and SMM (n = 93). Patients with a marked predominance of aPCs/BMPC (≥ 95%) at diagnosis displayed a significantly higher risk of progression both in MGUS and SMM (P< .001). Multivariate analysis for progression-free survival (PFS) selected the percentage aPC/BMPC (≥ 95%) as the most important independent variable, together with DNA aneuploidy and immunoparesis, for MGUS and SMM, respectively. Using these independent variables, we have identified 3 risk categories in MGUS (PFS at 5 years of 2%, 10%, and 46%, respectively; P< .001) and SMM patients (PFS at 5 years of 4%, 46%, and 72%, respectively; P < .001). Our results show that multiparameter FC evaluation of BMPC at diagnosis is a valuable tool that could help to individualize the follow-up strategy for MGUS and SMM patients.