Prognostic factors associated with progression of smoldering multiple myeloma to symptomatic form



This article is corrected by:

  1. Errata: Erratum Volume 119, Issue 6, 1289, Article first published online: 26 November 2012

  • We are grateful to professor Giovanni Codacci Pisanelli for his critical review of the manuscript.

  • In addition to the authors, the following investigators (listed in alphabetic order) participated in the study: A. Andriani, MD, Hematology, Nuovo Regina Margherita Hospital (Rome); L. Annino, MD, Hematology, S. Giovanni Addolorata Hospital (Rome); G. Avvisati, MD, PhD, Hematology, Stem Cell Transplantation, Transfusion Medicine and Cellular Therapy Unit, University “Campus Bio-Medico” (Rome); A. Bagnato, MD, Hematology, Sandro Pertini Hospital (Rome); m. Cantonetti is Hematology Unit , Tor Vergata, Rome; p De Fabritis IS Hematology Unit, S. Eugenio Hospital Rome; I. Majolino, MD, Hematology Unit, S. Camillo Hospital (Rome); B. Monarca, MD, Hematology, S. Andrea Hospital (Rome); C. Petti, MD, Department of Hematology, Regina Elena National Cancer Institute (Rome).



Smoldering multiple myeloma (SMM) presents a high risk of progression to symptomatic MM (sy-MM). Herein, we analyzed some predictors of development of sy-MM. In 144 patients with SMM, we also compared the risk of progression predicted by bone marrow plasma cell (BMPC) involvement on the bone marrow biopsy (BMB) versus bone marrow aspirates (BMA).


From January 1980 to July 2010, 397 patients with SMM observed in 12 centers of the Multiple Myeloma GIMEMA (Gruppo Italiano Malattie EMatologiche dell'Adulto) Latium Working Group have been analyzed. At progression to sy-MM, the severity of clinical presentation was graded according to the need of intensive supportive care.


After a median follow-up of 135 months, the cumulative incidence of progression rates to sy-MM were 45%, 55%, and 75% at 10, 15, and 20 years, respectively. Hemoglobin ≤12.5 g/dL, monoclonal component ≥2.5 g/dL, and BMPC ≥60% were the only parameters negatively affecting the cumulative incidence of progression. In particular, 10 of 397 (2.5%) patients with BMPC ≥60% had a 5.6-fold increased risk of fast progression (within 2 years), which occurred with severe clinical manifestations in 62% of cases. BMB was more sensitive for the detection of BMPC involvement, even though BMA was a more reliable indicator of a rapid progression to sy-MM.


The highest risk of rapid evolution to sy-MM and the severity of clinical manifestation at the progression suggest that SMM patients with a BMPC ≥60% should be treated soon after diagnosis. Moreover, BMPC is a more reliable index for progression to sy-MM if assessed by BMA. Cancer 2012. © 2012 American Cancer Society.