Table 1.
Studies predicting risk of progression of SMM to symptomatic MM.
| Author [year] | Included number and criteria | Risk factors | Outcome |
|---|---|---|---|
| Kyle et al. [2007] [15] | 276 IMWG | Group 1 (BMPC ≥ 10% and M protein ≥ 30 g/L); group 2 (BMPC ≥ 10% and M protein < 30 g/L); group 3 (BMPC < 10% and M protein ≥ 30 g/L) | TTP: group 1: 2 y; group 2: 8 y; group 3: 19 y |
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| Kastritis et al. [2013] [16] | 96 IMWG | Risk factor 1: M protein ≥ 30 g/L; risk factor 2: extensive BM infiltration ≥ 60%; risk factor 3: FLC ratio ≥ 100; risk factor 4: abnormal MRI | TTP: with risk factor 1 was 2 y (versus 8 y without risk factor 1); with risk factor 2 was 15 m (versus 90 m without risk factor 2); with risk factor 3 was 18 m (versus 73 m without risk factor 3); with risk factor 4 was 15 m (versus not reached without risk factor 4). |
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| Rajkumar et al. [2011] [17] | 655 IMWG | BMPC ≥ 60% | 2-y progression rate: 95%; TTP: 7 m |
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| Pérez-Persona et al. [2007] [19] | 93 IMWG | Group 1: neither aPCs/BMPC ≥ 95% nor immunoparesis; group 2: aPCs/BMPC ≥ 95% or immunoparesis; group 3: aPCs/BMPC ≥ 95% and immunoparesis | 5-y progression rate: group 1: 4%; group 2: 46%; group 3: 72% |
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| |||
| Pérez-Persona et al. [2010] [20] | 61 IMWG | aPCs/BMPC ≥ 95% | 3-y progression rate: for evolving SMM with aPCs/BMPC ≥ 95% was 46% (versus 8% with aPCs/BMPC < 95%); for nonevolving SMM with aPCs/BMPC ≥ 95% was 15% (versus no progressions with aPCs/BMPC < 95%) |
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| Larsen et al. [2013] [21] | 586 IMWG | FLC ratio ≥ 100 | TTP: FLC ratio ≥ 100: 15 m; FLC ratio < 100: 55 m |
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| Dispenzieri et al. [2008] [22] | 273 IMWG | BMPC ≥ 10%; M protein ≥ 30 g/L; FLC ratio ≥ 8; low-risk: 1 risk factor; intermediate-risk: 2 risk factor; high-risk: 3 risk factor | 5-y progression rate: low-risk: 25%; intermediate-risk: 51%; high-risk: 76% |
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| Witzig et al. [1994] [23] | 57 BMPC > 10% without CRAB | Abnormal PBPC (an increase in number or proliferative rate of PBPC) | TTP: with abnormal PBPC was 0.75 y (versus 2.5 y without abnormal PBPC) |
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| Bianchi et al. [2013] [24] | 91 IMWG | High PBPC (absolute PBPC > 5000 × 106/L and/or >5% cytoplasmic Ig positive PC per 100 PBMC) | 2-y progression rate: with high PBPC was 71% (versus 25% without high PBPC); 3-y progression rate: with high PBPC was 86% (versus 34% without high PBPC) |
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| Rosiñol et al. [2003] [25] | 53 BMPC > 10%, M-protein > 30 g/L or light chain > 1 g, hemoglobin > 100 g/L, without CRAB | Evolving SMM (a progressive increase in M protein, a previously recognized MGUS and a significant higher proportion of IgA type) | TTP: with evolving SMM was 1.3 y (versus 3.9 y with nonevolving SMM) |
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| Moulopoulos et al. [1995] [26] |
38 BMPC > 10%, hemoglobin > 105 g/L, normocalcemia, M protein < 45 g/L, and no lytic bone lesion | Abnormal MRI | TTP: with abnormal MRI was 16 m (versus 43 m with normal MRI) |
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| Hillengass et al. [2010] [27] | 149 IMWG | Focal lesions > 1 | 2-y progression rate: 0 or 1 focal lesion: 20%; >1 focal lesion: 70% |
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| Neben et al. [2013] [28] | 248 IMWG | del (17p13), t(4;14), +1q21 and hyperdiploidy | TTP: with del (17p13) was 2.04 y (versus 5.62 y without del (17p13)); with t(4;14) was 2.91 y (versus 5.71 y without t(4;14)). 3-y progression rate: with +1q21 was 43% (versus 27% without +1q21); with hyperdiploidy was 35% (versus 29% without hyperdiploidy) |
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| Rajkumar et al. [2013] [29] | 351 IMWG | Low-risk: no detectable abnormalities; Standard-risk: t(11;14), MAF translocations, other/unknown IgH translocations, or monosomy 13/del (13q); Intermediate-risk: trisomies alone; High-risk: t(4;14) | TTP: High-risk: 28 m; Intermediate-risk: 34 m; Standard-risk: 55 m; Low-risk: not reached |
PC: plasma cells; PBPC: peripheral blood plasma cells; PBMC: peripheral blood mononuclear cells; Ig: immunoglobulin; MRI: magnetic resonance imaging; FLC: serum free light chain; BMPC: bone marrow plasma cells; aPCs/BMPC: aberrant plasma cells within the bone marrow plasma cells; TTP: median time to progression; CRAB: hypercalcemia, renal failure, anemia, and bone lesions; IMWG: International Myeloma Working Group; m: month; y: year.