Excellent Long-Term Survival of Patients with Waldenström‘s Macroglobulinemia (WM) treated in Private Oncology Practices and a University hospital with different Treatment Strategies

WM is a rare type of malignant B-cell lymphoma, defined as a lymphoplasmocytic lymphoma in bone marrow and a monoclonal gammopathy of immunoglobulin-M (IgM) type. Due to the paucity of large clinical trials, a standard treatment regimen is still controversial. The purpose of this study was to compare the standard treatment and outcome of patients (pts) treated in private oncology practices (PP) and a university hospital (UH) in a region of southern Germany (Nordbaden).

We retrospectively reviewed the charts of all pts with WM of the last 2 decades of 4 PP in Mannheim, Heidelberg, Karlsruhe and Speyer and the department of hematology of the University of Heidelberg.

170 patients with WM could be identified, 74 from PP, 96 from the UH. The median age of the 170 pts was 63.3 years (range 29.1–88.5). The clinical symptoms were splenomegaly in 21.2%, hyperviscosity in 15.9%, lymphadenopathy in 15.9%, and polyneuropathy in 11.2%. 12.9% had a previous phase of IgM-MGUS. Pts from PP were older (median 65.3 vs. 62.5, p=0.01). Mean hemoglobine level at diagnosis was lower in pts from UH (11.4 vs. 12.2, p=0.04). There was no significant difference in mean platelet count, IgM and ß2-microglobuline level at diagnosis. 54% of pts from PP have received treatment during the observation time, as compared to 78.1% of the UH (p<0.001). The most common first line treatment protocols of PP were Chlorambucil (17/40, 42.5%), Bendamustin (17.5%) and Rituximab(R)-Bendamustin (17.5%). The UH most commonly administered R-Pentostatin-Cyclophosphamide (28%), Chlorambucil (17.3%) and COP (16%). 35% of the treated pts of PP have received R, as compared to 62.6% of the pts of the UH (p<0.001). 60% of the treated pts of PP have received Bendamustin, as compared to 8% of the pts of the UH (p<0.001). The time to first treatment was significantly shorter in pts from the UH (median 13.7 mo.) as compared to PP (52.9 mo.) (p=0.05). Median overall survival of all pts was 25.0 yrs and did not differ between PP and UH.

Pts with WM treated in PP were older and had higher initial hemoglobin levels as compared to pts from the UH. Treatment differs significantly between PP and UH. Time to first treatment was significantly shorter in pts from UH. Overall survival was excellent, and better than reported previously.

Hensel:Roche: Honoraria, Research Funding; Mundipharma: Research Funding.