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.