Poster Session I: Indolent and mantle-cell non-Hodgkin lymphoma - Clinical
Waldenström Macroglobulinemia (WM) is a rare, indolent B-cell lymphoplasmacytic malignancy. Patient outcomes are highly heterogeneous, with a proportion of patients surviving less than 5 years (short survivors) and another proportion that survive longer than 10 years. The laboratory parameters in the currently used International Prognostic Scoring System for WM (IPSSWM) include hemoglobin, serum IgM, platelet count, and serum β2-microglobulin.
We aim to identify unique patient characteristics and prognostic features associated with short survival in WM.
The medical records of patients with active WM that were diagnosed at Mayo Clinic Rochester, Arizona, and Florida between January 1st, 1996 and December 31st, 2013 were reviewed. The patients with smoldering WM were excluded. Cohorts of patients who either survived ≤ 5 years (Short Survival Group) or those with an overall survival (OS) ≥ 10 years (Long Survival Group) from the diagnosis of active disease were compared. Survivors with a follow-up of ≤ 5 years were not included in the analyses. Two-sided Wilcoxon rank sum test and Chi square/Fisher's exact test were used to compare the continuous and categorical variables, respectively. The variables that were statistically significant on univariate analysis (P < 0.05) were included in a multivariate logisitic regression analysis.
Of 893 consecutively seen WM patients (median follow-up of 9 years [95% CI 8.4-9.7]), we identified 387 patients who could be categorized into either the Short Survival Group (n = 171 patients, 44%) or the Long Survival Group (n = 216, 56%). The Short Survival Group had a median OS of 2.4 years (2.1-2.8) and median age at diagnosis of 73 years (42-93), while the Long Survival Group (n = 216, 56%) had a median OS of 18.9 years (16-NR) and median age at diagnosis of 62 years (31-85). The baseline characteristics and significant findings between the two groups are listed in the Table. Parameters significant on univariate analysis included age >65 years, albumin < 3.5 g/dL, β2-microglobulin >3 μg/ml, and LDH > upper limit of normal (ULN). On multivariate analysis, albumin <3.5 g/dL and LDH > ULN were independently associated with short survival. Among the Long Survivors, 60 (28%) patients survived 15 years or more.
Lactate dehydrogenase above the ULN and serum albumin <3.5 g/dL are independent biomarkers of short survival in WM. The MYD88L265P status and the size of serum IgM are not prognostic in WM. Our data suggest the need for simplification of the current staging system with the use of widely available markers: serum albumin and lactate dehydrogenase.