Survival patterns among venous thromboembolism patients with hematologic malignancies in Alberta, Canada from 2003 to 2015

Background: Hematologic malignancies are at increased risk of developing venous thromboembolism (VTE).

Objectives: We aimed to identify the prevalence of hematologic malignancy in VTE patients and compare the survival with or without VTE.

Methods: Using linked administrative data and a validated algorithm we identified VTE cases in Alberta, Canada from 2003 to 2015. Subjects having International Classification of Diseases code for hematologic malignancies, solid tumors and both cancers within 1 year before and after the VTE index event were defined as cancer associated VTE cases. We also identified patients with no VTE. Cox proportional hazards model was applied to estimate the hazard ratio (HR) of death. Kaplan Meier analysis was performed to compare survival rate between different groups.

Results: We identified 5157 cancer associated VTE patients and 24,932 cancer patients with no VTE. Among the cancer associated VTE patients 697 (13.5%), 4376 (84.9%) and 84 (1.6%) had hematologic malignancies, solid tumors and both cancers, respectively. The median survival (in months) was significantly shorter in myelodysplastic syndrome (MDS), myeloproliferative neoplasm (MPN) and plasma cell dyscrasia patients with VTE than those without (16.6 vs 27.1, p = 0.004; 70.6 vs 99.2, p = 0.023 and 32.9 vs 55.5, p = 0.007 respectively). Occurrence of pulmonary embolism in MDS and MPN patients and deep vein thrombosis in plasma cell dyscrasia patients were significantly associated with increased risk of death (adjusted HR: 3.0, 95% CI: 1. 46-6.16; adjusted HR 1.60, 95% CI:1.01-2.51 and adjusted HR: 1.40, 95% CI: 1.03-1.89 respectively).

Conclusions: VTE adversely affects the survival among patients with hematologic malignancies.