Bence Jones proteinuria in smoldering multiple myeloma as a predictor marker of progression to symptomatic multiple myeloma

• Published in: Leukemia Vol. 30; no. 10; pp. 2026 - 2031
• Main Authors: González-Calle, V, Dávila, J, Escalante, F, de Coca, A G, Aguilera, C, López, R, Bárez, A, Alonso, J M, Hernández, R, Hernández, J M, de la Fuente, P, Puig, N, Ocio, E M, Gutiérrez, N C, García-Sanz, R, Mateos, M V
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 01-10-2016; Nature Publishing Group
• Subjects: 692/699/1541/1990/804; 82/1; 82/29; Adult; Aged; Aged, 80 and over; Analysis; Bence Jones Protein - urine; Biological markers; Biomarkers, Tumor - urine; Cancer Research; Capillary electrophoresis; Care and treatment; Confidence intervals; Critical Care Medicine; Development and progression; Diagnosis; Disease Progression; Female; Hematology; Humans; Identification and classification; Independent variables; Intensive; Internal Medicine; Leukemia; Magnetic resonance imaging; Male; Medicine; Medicine & Public Health; Middle Aged; Multiple myeloma; Multiple Myeloma - diagnosis; Multiple Myeloma - urine; Oncology; original-article; Physiological aspects; Plasma; Proteins; Proteinuria; Retrospective Studies; Risk Assessment; Risk groups; Smoldering; Subgroups; Time Factors; Urine; Spain
• ISSN: 0887-6924; 1476-5551
• DOI: 10.1038/leu.2016.123

The diagnosis of smoldering multiple myeloma (SMM) includes patients with a heterogeneous risk of progression to active multiple myeloma (MM): some patients will never progress, whereas others will have a high risk of progression within the first 2 years. Therefore, it is important to improve risk assessment at diagnosis. We conducted a retrospective study in a large cohort of SMM patients, in order to investigate the role of Bence Jones (BJ) proteinuria at diagnosis in the progression to active MM. We found that SMM patients presenting with BJ proteinuria had a significantly shorter median time to progression (TTP) to MM compared with patients without BJ proteinuria (22 vs 88 months, respectively; hazard ratio=2.3, 95% confidence interval=1.4–3.9,
P=
0.002). We also identified risk subgroups based on the amount of BJ proteinuria: ⩾500 mg/24 h, <500 mg/24 h and without it, with a significantly different median TTP (13, 37 and 88 months,
P<
0.001). Thus, BJ proteinuria at diagnosis is an independent variable of progression to MM that identifies a subgroup of high-risk SMM patients (51% risk of progression at 2 years) and ⩾500 mg of BJ proteinuria may allow, if validated in another series, to reclassify these patients to MM requiring therapy before the end-organ damage development.