Short-Term Risk for Progression in Patients with Smoldering Multiple Myeloma: The Impact of CD56 Expression

• Published in: Blood 2020-11, Vol.136 (Supplement 1), p.11-11
• Main Authors: Notarfranchi, Laura, Vescovini, Rosanna, Segreto, Roberta, Bonomini, Sabrina, Storti, Paola, Marchica, Valentina, Costa, Federica, Sammarelli, Gabriella, Todaro, Giannalisa, Catarozzo, Maria Teresa, De Giovanni, Dario, Fabiano, Vincenza, Dalla Palma, Anna Benedetta, Giuliani, Nicola
• Format: Article
• Language: English
• ISSN: 0006-4971; 1528-0020
• DOI: 10.1182/blood-2020-139214

The identification of risk factors for progression is critical in the clinical management and appropriate follow up of patients with Smoldering Multiple Myeloma (SMM). The early identification of patients with possible short-term progression to Multiple Myeloma (MM) could lead to anticipate the treatment. Several prognostic score identify in SMM patients the main risk factors for progression to MM. The two most used risk stratification models in SMM are the Mayo Clinic model, based on the tumor burden and the free light chains ratio, and the Spanish PETHEMA group model based on the immunophenotyped to identify abnormal plasma cells (PCs) and the reduction of the unevolved immunoglobulins. However, significant discrepancies between these two clinical models currently used in clinical practice has been recently underlined. For this reason, new parameters to identify possible new parameters for progression in SMM need to be defined. The aim of this study was to validate the main prognostic score and to investigate the possible role of the immunphenotype as risk factor for progression in a monocentric cohort of patients with SMM. We retrospectively evaluated a cohort of SMM patients admitted to a single haematological center (Hematology and BMT Unit, University Hospital of Parma) between 2014 and 2018. We analyzed a total cohort of 80 patients diagnosed with SMM according to the IMWG recently updated diagnostic criteria. All patients analysed underwent to Bone Marrow (BM) examination and imaging evaluation was performed in order to exclude the presence of bone disease and/or focal lesions. Both immunophenotypic and FISH analysis were performed of BMPCs. The median age of the SMM patients analysed was 68 years (range 36-93 years). Median percentage of BMPCs was 15% (range 10-40%) in the entire population. Median serum M-protein was 2 g/dL (range: 0.17-4.5). FLC ratio value was available in 66 patients: in 47 (71%) the ratio was unbalanced, 26 (39%) had a FLC ratio ≤ 0.125 or ≥ 8 and in 6 (9%) it was > 20. The presence of a reduction of one or two uninvolved immunoglobulins occurred in 61% of the entire population. The median follow up time was 27 months (range 0 - 76 months) for whole population. Overall 22 patients of the entire cohort progressed to MM with a median the time to progression (TTP) of 22 months. Firstly, we validated the currently score of progression in our cohort of SMM patients. By univariate analysis we found that percentage of BMPCs, abnorma