Patient characteristics and long–term outcomes beyond the first 6 months after a diagnosis of cancer-associated venous thromboembolism

Little is known about the clinical course and treatment decisions in patients with cancer-associated venous thromboembolism (VTE) beyond the initial treatment period of 3 to 6 months. This information is important for clinicians and patients to inform their decisions regarding duration of anticoagulation. We reviewed health records from consecutive patients referred to our institution for cancer-associated VTE management between 2013 and 2015 to describe their clinical course and outcomes from 6 to 24 months following their index VTE. Details on patient and cancer characteristics, objectively documented recurrent venous thromboembolism (rVTE), clinically relevant bleeding (CRB) and overall mortality were captured. 524 patients met eligibility criteria and 322 were alive at 6 months after the index VTE. At 6 months, anticoagulation was continued in 222 patients (68.9%). During follow-up, there were 33 rVTE events in 30 patients (1-year cumulative incidence of 8.2%; 95% CI: 5.5%–11.6%), and 16 CRB events in 15 patients (1-year cumulative incidence of 4.1%; 95% CI: 2.3%–6.7%); 20 (60.6%) rVTE events and 13 (81.3%) CRB events occurred while on anticoagulation. One-year survival beyond 6 months was 73.7% (95% CI: 68.5%–78.2%). A higher proportion of patients with advanced cancer and receiving cancer treatment was found among those who continued anticoagulation beyond 6 months compared to those who stopped anticoagulation. Patients with cancer-associated VTE who are alive at 6 months after VTE diagnosis remain at high risk of rVTE, CRB and death. •Outcomes of patients with cancer-associated VTE beyond 6 months are uncertain.•524 consecutive unselected patients were examined from 2013 to 17 at a single center.•Anticoagulation was continued at 6 months in 68.9%; 85.1% used LMWH.•Between months 6–24, 9.3% had recurrent thrombosis and 4.7% had bleeding.•1-year mortality between months 6–18 was 26.3%.