A first Czech analysis of 1887 cases with monoclonal gammopathy of undetermined significance

Eur J Haematol. 2017 Jul;99(1):80-90. doi: 10.1111/ejh.12894. Epub 2017 May 11.


Introduction: Monoclonal gammopathy of undetermined significance (MGUS) is a premalignant condition with a risk of malignant conversion.

Patients and methods: With the aim to estimate the cumulative risk MGUS progression to hematologic malignancies, we analyzed a nationwide population-based cohort of 1887 MGUS patients from the Czech Registry of Monoclonal Gammopathies (RMG) between 2007 and 2013.

Results: During the follow-up period (median 4 years; range 0.6-34.8), progression to hematologic malignancies was observed in 8.6% (162 of 1887) of patients. Factors associated with progression were as follows: M-protein concentration ≥1.5 g/dL, pathological sFLC (<0.26 or >1.65) ratio, bone marrow plasma cells (BMPCs) in cytology >5%, immunoparesis, age ≥69 years, and the level of serum hemoglobin at baseline <12.0 g/dL. Combining these factors, we propose a new risk model (CMG model). The risk of progression at 10 years was 1.6%, 16.9%, 22.9%, 39.4%, and 52.3%, respectively, if 0 (reference group), one, two, three, or four to five risk factors are present (P<.001) with HR 63 times higher compared to the reference MGUS group.

Conclusion: The new CMG model was established with an advantage for better identification of MGUS patients at low risk.

Keywords: monoclonal gammopathy; multiple myeloma; progression; risk factors.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Biomarkers
  • Bone Marrow / pathology
  • Cell Transformation, Neoplastic
  • Czech Republic / epidemiology
  • Disease Progression
  • Female
  • Humans
  • In Situ Hybridization, Fluorescence
  • Kaplan-Meier Estimate
  • Male
  • Middle Aged
  • Monoclonal Gammopathy of Undetermined Significance / diagnosis
  • Monoclonal Gammopathy of Undetermined Significance / epidemiology*
  • Monoclonal Gammopathy of Undetermined Significance / metabolism
  • Myeloma Proteins / metabolism
  • Plasma Cells / metabolism
  • Plasma Cells / pathology
  • Population Surveillance
  • Proportional Hazards Models
  • Registries
  • Risk Assessment
  • Risk Factors


  • Biomarkers
  • Myeloma Proteins
  • multiple myeloma M-proteins