Table 2 Prognostic factors

At diagnosis

SBP vs. EMP

Higher risk for progression to MM for SBP patients (progression rate of 65–84% at 10 years) compared to EMP patients (25–35% at 10 years)

[36, 47]

Bone marrow plasmacytosis detected by flow cytometry*

Minimal bone marrow plasmacytosis is associated with decreased progression-free survival

[37]

Bone marrow plasmacytosis detected by flow cytometry

About 70% of patients with minimal bone marrow plasmacytosis progress to MM with a median time to progression of 26 months

[10, 11]

Serum SFLC ratio

An abnormal serum FLC ratio is associated with a higher risk of progression to MM compared to a normal SFLC ratio (44 vs. 26% at 5 years and 51 vs. 32% at 10 years)

[38]

Histological abnormalities

Histologic score and degree of angiogenesis have prognostic value

[40, 41]

At follow-up

Persistence of a serum monoclonal protein after treatment

9% of progression for patients with resolved serum monoclonal protein vs. 71% of progression for patients with persistent serum monoclonal protein.

[42]