Prognostic factors and primary treatment for Waldenström macroglobulinemia - a Swedish Lymphoma Registry study

We present a nationwide prospective Swedish registry-based study of Waldenström macroglobulinaemia (WM), that focuses on incidence and survival in relation to clinical prognostic factors and primary systemic therapies. A total of 1511 patients with WM and lymphoplasmocytic lymphoma (LPL) were registered in the Swedish Lymphoma Registry (SLR) between 1 January 2000 and 31 December 2014. The age-adjusted incidence of WM/LPL was 11·5 per million persons per year, three times higher than the reported incidence worldwide. Medical records were retrieved for 1135 patients (75%). A retrospective review showed that 981 (86·1%) of these patients fulfilled the World Health Organization diagnostic criteria for WM and these patients were analysed further. The overall survival (OS) improved between two periods - 2000-2006 and 2007-2014 - with a five-year OS of 61% and 70%, respectively. Significant prognostic factors for OS, evaluated at the time of diagnosis, were age, elevated lactate dehydrogenase level and haemoglobin ≤115 g/l for patients receiving therapy 0-3 months after diagnosis, and age, poor performance status, haemoglobin ≤115 g/l, and female sex in "watch and wait" patients (multivariable analysis). The level of the IgM monoclonal immunoglobulin had no significant prognostic value. Rituximab included in first-line therapy was associated with improved survival.