No significant improvement in the outcome of patients with Waldenström's macroglobulinemia treated over the last 25 years

The treatment of Waldenström's macroglobulinemia (WM) has changed over the last decades, mainly because of the introduction of nucleoside analogues and of rituximab while novel agents such as bortezomib have been recently introduced. We performed an analysis to investigate whether the outcome of patients with WM has improved over the last years, compared to that of patients who started treatment before new drugs became widely available, especially as part of the frontline treatment. We analyzed 345 symptomatic patients with WM: 130 who initiated treatment before and 215 who started treatment after January 1, 2000. Patients who started treatment in the latter group were older and had more often elevated beta2-microglobulin but the other characteristics were similar between the two groups. Most patients who started treatment before January 1, 2000 were treated upfront with alkylating agent-based regimens and most patients who started treatment after January 1, 2000 received rituximab-based regimens as initial treatment. Objective response (63 and 59%, respectively) and median overall survival, OS, (106.5 months for Group A and is estimated at 94 months for Group B, P = 0.327) were similar. There was also no difference regarding OS or cause specific survival (CSS) in each risk group according to IPSSWM. Our observation may be explained by the indolent course of WM in several patients and by the lack of profound cytoreduction in patients with high-risk disease. Possible differences in the 15- or 20-year survival rate between the two groups may be detected with further follow-up of these patients.