Management and outcomes of cancer-associated venous thromboembolism in patients with concomitant thrombocytopenia: a retrospective cohort study

Venous thromboembolism (VTE) and thrombocytopenia are both more common in cancer patients than in general populations. Both the outcomes and optimal management of cancer-associated VTE in thrombocytopenic patients are unknown. The objective of the current  study is to describe a cohort of patients presenting with acute cancer-associated VTE with concomitant thrombocytopenia, including management patterns and outcomes. We conducted a retrospective cohort study of all cancer patients admitted to a regional cancer centre and the main university hospital’s hematology service in Edmonton, Alberta, from 2005–2011, who had thrombocytopenia at the time of acute VTE. We report rates of recurrent symptomatic thromboembolism, major and clinically relevant non-major bleeding, within the initial 3 months following VTE diagnosis. Seventy-four patients were identified as eligible and reviewed. Seventeen (23.0 %) patients did not receive any antithrombotic therapy, 30 (40.5 %) received a minimum of 3 months of full-dose anticoagulation, and 27 (36.5 %) received partial treatment, which was either dose-reduced, interrupted, or shortened in duration. Twenty-three (31.1 %) experienced recurrent thromboembolism and 13 (17.6 %) had bleeding events, of which 3 (4.1 %) were major. In conclusion, patients with acute cancer-associated VTE and concomitant thrombocytopenia were managed heterogeneously at our institution, without a predominant strategy. There was a high rate of short-term complications, including recurrent thromboembolism and hemorrhage in this cohort. Future research should focus on determining the optimal management strategy in this challenging clinical scenario.