International Prognostic Scoring System for Waldenström macroglobulinemia (ISSWM)

Prognostic score for Waldenström macroglobulinemia (lymphoplasmacytic lymphoma with IgM paraprotein)

Applies to symptomatic patients requiring first-line therapy.

1. Sum the number of risk factors

ISSWM risk factors
Age > 65 years (advanced age alone = intermediate risk)
Hemoglobin ≤ 11.5 g/dL
Platelet count ≤ 100 x109/L
Serum Β2-microglobulin > 3 mg/L
Serum monoclonal protein > 70 g/L

2. Determine risk category and prognosis

Risk factorsRisk category% of patientsMedian survival (months)
0 or 1 (except age)Low27142
Any 2, or age aloneInter­mediate3899
≥ 3High3543

The International Prognostic Scoring System for Waldenström macroglobulinemia (ISSWM) applies to symptomatic patients requiring first-line therapy. The ISSWM derives from a multivariate analysis of survival of 587 patients who were diagnosed and started treatment before 2002.1 All patients presented with serum monoclonal IgM and bone marrow involvement by lymphoplasmacytic lymphoma.

Indications for starting therapy were cytopenias (51%), constitutional symptoms (44%), organomegaly (35%), hyperviscosity (31%) or IgM-related symptoms (13%). IgM-related symptoms were defined as severe neuropathy, symptomatic nephropathy, systemic amyloidosis, symptomatic cryoglobulinemia, or cold agglutinin disease. The majority of patients were treated with an alkylating agent alone (63%) or with fludarabine alone (32%).

The prognostic relevance of the ISSWM has been validated in a separate series of patients treated with rituximab alone or in combination with dexamethasone and cyclophosphamide.2