Epidemiology of venous thromboembolism in hematological cancers: The Scandinavian Thrombosis and Cancer (STAC) cohort.

Introduction: Venous thromboembolism (VTE) is an important cause of morbidity and mortality in cancer patients, however the risk of VTE differs according to cancer type. Hematological cancers have varying phenotypes. Incidence rates (IR) of VTE in different hematological cancer types have not been investigated in a cancer-exposed subset of the general population.

Methods: In a population-based cohort, we estimated incidence rates of VTE among patients with six subtypes of hematological cancer and among age and sex matched reference subjects.

Results: During a mean follow-up of 4.8years, 30 objectively confirmed first-time symptomatic VTEs occurred among 838 subjects with hematological cancer. The IR of VTE was higher in all types of cancer except for indolent lymphoma but including chronic lymphocytic leukemia compared with reference subjects both during the first year after cancer diagnosis and 1-5years after diagnosis. IR of VTE for indolent lymphoma was not higher than controls.

Conclusion: The IRs of VTE were increased in all types of hematological cancer (including chronic lymphocytic leukemia) compared with reference subjects except indolent lymphomas.