Initial Features and Outcome Are Similar in Patients with Lymphoplasmacytic Lymphoma Regardless They Meet or Not Criteria of Waldenström Macroglobulinemia,
Authors: Giné Eva , Rovira Jordina , Martinez-Trillos Alejandra , Villamor Neus , Martinez Antonio , Gutierrez-Garcia Gonzalo , Colomo Luis , Delgado Julio , Baumann Tycho Stephan , Campo Elias , Rozman María , Lopez-Guillermo Armando 
Published: October 2019

Abstract
Abstract 3677
Lymphoplasmacytic lymphoma (LPL) is a very heterogeneous disease from the clinical stand point, including the fact that Waldenström macroglobulinemia (WM) can be recognized in a significant proportion of LPL cases. Whether LPL with and without criteria for WM differ in the clinical features and outcome is not well known and is the aim of the present study. For this purpose, 50 patients (median age, 67 years (range, 19 to 91; 50% males) with a tissue biopsy diagnostic of LPL or a bone marrow infiltration by LPL were included in the present study. Main clinic-biological characteristics and outcome were recorded and analysed. Bone marrow infiltration and presence of a serum paraprotein were observed in 42 cases (89%) and 37 cases (86%), respectively. WM according to WHO criteria was identified in 26 patients (60%). Thirty-four patients received treatment for LPL (69%), including rituximab at any time in 74% of treated patients. The main clinical features of the series according to the WM/LPL or non-WM/LPL criteria are listed in the table. No relevant differences were identified when comparing WM cases with remaining LPL cases, except for those determined by their definition. Six patients eventually developed solid neoplasms with no differences between both groups. After a median follow-up of 35 months (range 0,3 to 209), 17 patients have died, including 10 patients by disease progression, 2 by secondary malignancies, 2 by heart failure, and 3 by unknown causes. The median survival of the whole series was 133 months (CI 95%: 40–226). Among the ten patients who died as a result of disease progression, two different patterns were observed. In six cases disease progression was characterized by general symptoms and lymph node growth, whereas the other 4 cases showed severe cytopenias unresponsive to treatment. These patterns were both observed indistinctly in WM and the non-WM/LPL cases. OS was similar in both groups of patients (median OS 133 vs. 216 months in WM and non-WM, respectively; p=NS). In conclusion, no major differences were observed in terms of initial features and outcome among LPL patients according to the definition of WM or non-WM/LPL.FeaturesAll patients (n=50)WM/LPL patients (n=26)Non-WM /LPL patients (n= 24)Age (median, yrs)676668Gender (male, %)25 (50%)12 (46%)13 (54%)Stage IV (%)46 (94%)26 (100%)20 (87%)Bone marrow infiltration44 (90%)26 (100%)*18 (78%)*Serum paraprotein37 (86%)26 (100%)*11 (65%)*IgM type30 (81%)26 (100%)*4 (36%)*M size (median, g/L)181815.3ECOG ≥ 2 (%)8 (18%)2 (9%)6 (29%)Enlarged lymph nodes17 (37%)8 (33%)9 (41%)Splenomegaly12 (26%)5 (20%)7 (33%)Bulky disease7 (15%)3 (12%)4 (18%)Hb (<100 g/L)14 (29%)8 (31%)6 (27%)Platelet (<100x 109/L)6 (13%)4 (15%)2 (10%)High serum LDH6 (13%)3 (12%)3 (15%)High serum beta-2-m19 (50%)10 (48%)9 (53%)No initial treatment21 (43%)13 (50%)8 (35%)# Treatments (median, range)2 (1–7)3 (1–7)*1 (1–4)*60-month overall survival (%)67% (51–83%)71% (51–91%)65% (41–89%)Significant p values for WM vs. non-WM*: bone marrow infiltration (p=.018), serum paraprotein (p=.002), IgM type (p=<.001), lines of treatment (p=.004).

Disclosures:
No relevant conflicts of interest to declare.