Gender disparities in Waldenstrom macroglobulinemia: Insights from a comprehensive analysis.

Abstract

e19064 Background: Waldenstrom Macroglobulinemia (WM) is a rare, complex hematological malignancy with paucity of research about the landscape of gender disparities regarding clinical phenotype, genotype and outcomes. The aim of our abstract to identify those gender-based variations in WM. Methods: This is a retrospective study using a large WM database at Moffitt Cancer Center (MCC). We reviewed the baseline characteristics and molecular information of patients evaluated at MCC from years 1995 to 2020 and outcomes based on gender. Chi-square tests were used for comparing categorical variables and t-test for continuous variables. Kaplan-Meier method was used to compare survival. Results: Total of 265 patients with WM were identified, 63% (167) were males and 37% (98) were females. Mean age at diagnosis was 76 years for both groups, most of the patients were white non-Hispanics (94% in men vs 96% in women) (P=0.09) and had performance status (PS) 0 at diagnosis, 63% in men, 70% in women. The table summarizes baseline characteristics based on gender, men had slightly lower hemoglobin mean 11.1 vs11.5 in women (P =0.013), lower platelet count mean 209 vs 264 in women (P=<0.001) and slightly lower albumin mean 3.8 vs 3.92 in women (P=0.0445). Hyperviscosity and plasmapheresis were more in women 10% vs 2% in men (P=<0.001), Cryoglobulinemia was more in men 11% vs 1% (P=<0.001). There were no statically significant gender differences based on the presence of mutations in MYD88, CXCR4, tp53, or del6q. The median overall survival (mOS) was slightly longer in lower-risk WM female pts, but not in high-risk (based on International Prognostic Scoring System for WM). The overall mOS was 98 months (mo) for females compared to 95 for males, P=0.004. The mOS for low-risk WM was 137 vs 132 mo, for intermediate risk 89 vs 87 mo, and for high-risk 37 vs 39 mo respectively for females and males (P=<0.001). The rate of Diffuse Large B Cell Lymphoma transformation was not different (7% and 4%, respectively for women and men, (P=0.11) Women were more likely to respond to Bendamustine + Rituximab (BR)/BR + steroids than men (43%vs 25%, p=0.04)There were no differences in response to Cytoxan+ Rituximab+ Prednisone, Bruton’s tyrosine kinase inhibitors, or Venetoclax treatment. Conclusions: This retrospective review of a large database of WM patients highlights important gender differences in clinical WM disease features. Women had better overall survival, mainly in lower risk WM and higher responses to immunosuppressive therapy. Although disparities in WM may be multifactorial, disparities based on gender needs more studies to be explored for better understanding of the disease biology and outcomes. [Table: see text]