Predicting Survival in Waldenstrom Macroglobulinemia

Waldenstrom macroglobulinemia (WM) is a B-cell lymphoplasmacytic lymphoma characterized by the production of a monoclonal IgM paraprotein and frequent mutation of the MYD88 gene. Treatment options have evolved over the past 10 to 15 years to include immunochemotherapy, proteasome inhibitors, and Bruton tyrosine kinase inhibitors (BTKi). To develop an updated prognostic scoring metric, investigators conducted a retrospective analysis using a derivation cohort (n=341) from a single institution and an external validation cohort (n=335) from multiple sites.

Median follow-up was 8.2 years in the derivation cohort and 6.3 years in the validation cohort. Univariate and multivariate analyses in the derivation cohort identified three factors that were independently associated with overall survival (OS): age, serum lactate dehydrogenase (LDH) above the upper limit of normal (ULN), and serum albumin <3.5 g/dL. Points were assigned to these factors and risk groups were designated based on distinct OS outcomes in patients with different additive scores (see ).

In the current study cohorts, prognostic discrimination was improved — especially for intermediate-risk groups — with this new Modified Staging System for WM (MSS-WM) as compared with the earlier revised International Prognostic Scoring System (rIPSS-WM), which included beta-2-microglobulin level in addition to age, albumin level, and LDH level.