21.4. Guideline recommendations

Chapter 21

Assessment of baseline sFLCs is recommended by IMWG guidelines [42][20] and a European expert panel [1108] (Section 25.3.1) to assess risk of progression.

National Comprehensive Cancer Network® (NCCN®) guidelines also recommend sFLC analysis alongside serum protein electrophoresis (SPE) and sIFE in a panel of tests for surveillance/follow-up of solitary plasmacytoma after primary treatment (Section 25.8) [485]. Similar recommendations were recently reported by a European expert panel [1108]. They recommend that when measurable concentrations of a monoclonal protein or sFLCs are present, the IMWG uniform response criteria [905] be used for response assessment (Section 25.3.5).


  1. What is the reported 5-year risk of progression to MM in SPB patients with an abnormal κ/λ sFLC ratio?
  2. Based on the risk stratification model reported by Dingli et al. [472], which two factors can effectively discriminate SPB patients at low, medium and high risk of progression to MM?
  3. Which two risk factors were defined by Fouquet et al. [476] to identify solitary plasmacytoma patients at risk of progression to MM?


  1. 44% (Section 21.3).
  2. The κ/λ sFLC ratio at baseline and the persistence of a monoclonal immunoglobulin after 1 - 2 years (Section 21.3).
  3. An abnormal iFLC concentration and the presence of ≥2 hypermetabolic lesions by PET CT at baseline (Section 21.3).