Evolution of Management and Outcomes in Waldenström Macroglobulinemia: A Population-Based Analysis

Abstract

© AlphaMed Press 2016. Introduction. Waldenström macroglobulinemia/lymphoplasmacytic lymphoma (WM) is a rare lymphoma affectingolder patients. Its management largely relies on small phase II trials and it is unclear how their results translate into clinical practice in the community. Method. We evaluated changes in the presentation, management, and survival among 2,666 Medicare beneficiaries diagnosed with WM between 1994 and 2011, using Medicare claimslinkedto Surveillance, Epidemiology and End Results data. Results. Prevalence of transfusions, anemia, thrombocytopenia, and neuropathy at diagnosis significantly increased over time, whereas the use of plasmapheresis was low (2.5%) and stable. The proportion of patients starting chemotherapy within 1 year of WM diagnosis increased from 39% in 1994 to 62%in 2011(p < .0001).Treatments basedonclassic alkylators and purine analogs predominated in the 1990s, but were quickly replaced by rituximab-containing regimens after 2000. Rituximab monotherapy has been prescribed for > 50% of patients since 2004, and combination chemoimmunotherapy for a further 30%. Mostpatients initiating multiagent regimens in 2012–2013 received rituximab with bortezomib or bendamustine. These changes were accompanied by significant improvements in overalland WM-related survival, butalsobya significant increase in cost of chemotherapy. Mean Medicare payments for chemotherapy drugs accrued in the first year of treatment rose from $9,464 in 1994–2000 to $29,490 after 2008. Conclusion. Hematologists have rapidly adopted innovative, expensive therapies for WM before completion of randomized trials. This underscores theneedto assess the comparative valueof such therapies in rare malignancies through a combination of clinical and observational data.