Prognostic Value of Serum β2-Microglobulin in Patients with Waldenstrom’s Macroglobulinemia Requiring Treatment.

Introduction: Waldenstrom’s macroglobulinemia is a lymphoplasmacytoid lymphoma characterized by the production of monoclonal IgM. This disorder has a relatively indolent course with a median survival ranging from 5 to 10 years in different series. Several clinical and laboratory variables have been associated with an inferior survival such as advanced age, hyperviscosity, presence of cytopenias and hypoalbuminemia. More recently, serum beta2-microglobulin (beta2m) is being investigated for its potential role in stratifying patients with WM into different subsets.

Patients and methods: In order to further evaluate the role of serum beta2m we analyzed 124 patients with available pretreatment value of this variable. These patients received primary treatment consisting of alkylating agents, nucleoside analogues or rituximab. Their median age was 70 years (range 28 to 89 years) and their median survival was 105 months. Multiple clinical and laboratory parameters were evaluated for their possible correlation with overall survival for the whole patient population and for those 70 years of age.

Results: Age more than 70 years, the presence of B-symptoms, serum albumin <4g/dL and beta2m more than 4mg/dL were the main adverse predictive variables for survival. The median survival of patients with beta2m 4 and >4 mg/dL was 115 and 79 months respectively (p=0.01). In patients 70 years of age (N=63), beta2m >4mg/dL at the time of initial treatment was the only statistically significant factor in multivariate analysis associated with shorter survival (median 93 vs 143 months, for beta2m >4 vs ≤4 respsctively p=0,005).

Conclusions: We conclude that elevated serum 2m (>4 mg/dl) is an important parameter associated with inferior survival of patients with WM requiring treatment. Our observation that beta2m is the most significant variable associated with survival in younger patients with WM, indicates that this variable may be used for the selection of poor-risk patients candidates for high-dose therapy.