Asymptomatic Waldenstrom's macroglobulinemia.

A study was undertaken to evaluate the frequency and natural history of disease in patients with asymptomatic Waldenstrom's macroglobulinemia (WM). Among 132 consecutive, newly diagnosed patients with monoclonal IgM, 82 (27%) had symptomatic WM indicated by anemia, lymphadenopathy, or splenomegaly. Thirty-one patients had similar clinical features but were asymptomatic and followed without therapy until disease progression. There were 19 patients with monoclonal gammopathy of undetermined significance of IgM type (MGUS). In comparison to overt WM, patients with asymptomatic WM had significantly higher hemoglobin (Hgb) level (median, 12.1 v 9.7 g/dL), lower serum beta(2)-microglobulin (B(2)M) level (median, 2.4 v 3.4 mg/L), and similar IgM peaks (median, 2.2 and 1.8 g/dL). The IgM component was 3.6 g/dL or less in all patients with asymptomatic disease. For asymptomatic WM, median time to disease progression was 6.9 years with rare morbidity. Prognostic factors for early progression were Hgb <11.5 g/dL, B(2)M >or= 3.0 mg/L, and IgM peak >3.0 g/dL. Combinations of these variables defined three risk groups for progression with markedly different median times to progression of >5 years, 2 years, and 0.5 year, respectively. Response rate and survival after institution of treatment were similar to those of patients treated promptly for overt disease. We conclude that, among patients with WM, 27% were asymptomatic with slow disease progression before the need for chemotherapy. Since disease outcomes after treatment were similar to those of patients treated at diagnosis, patients with asymptomatic disease should be identified and followed without treatment for as long as risks of complications remain low.