Treatment and Long-Term Clinical Outcomes of Incidental Pulmonary Embolism in Patients With Cancer: An International Prospective Cohort Study.

PURPOSE: Pulmonary embolism is incidentally diagnosed in up to 5% of patients with cancer on routine imaging scans. The clinical relevance and optimal therapy for incidental pulmonary embolism, particularly distal clots, is unclear. The aim of the current study was to assess current treatment strategies and the long-term clinical outcomes of incidentally detected pulmonary embolism in patients with cancer. PATIENTS AND METHODS: We conducted an international, prospective, observational cohort study between October 22, 2012, and December 31, 2017. Unselected adults with active cancer and a recent diagnosis of incidental pulmonary embolism were eligible. Outcomes were recurrent venous thromboembolism, major bleeding, and all-cause mortality during 12 months of follow-up. Outcome events were centrally adjudicated. RESULTS: A total of 695 patients were included. Mean age was 66 years and 58% of patients were male. Most frequent cancer types were colorectal (21%) and lung cancer (15%). Anticoagulant therapy was initiated in 675 patients (97%), of whom 600 (89%) were treated with low-molecular-weight heparin. Recurrent venous thromboembolism occurred in 41 patients (12-month cumulative incidence, 6.0%; 95% CI, 4.4% to 8.1%), major bleeding in 39 patients (12-month cumulative incidence, 5.7%; 95% CI, 4.1% to 7.7%), and 283 patients died (12-month cumulative incidence, 43%; 95% CI, 39% to 46%). The 12-month incidence of recurrent venous thromboembolism was 6.4% in those with subsegmental pulmonary embolism compared with 6.0% in those with more proximal pulmonary embolism (subdistribution hazard ratio, 1.1; 95% CI, 0.37 to 2.9; P = .93). CONCLUSION: In patients with cancer with incidental pulmonary embolism, risk of recurrent venous thromboembolism is significant despite anticoagulant treatment. Patients with subsegmental pulmonary embolism seemed to have a risk of recurrent venous thromboembolism comparable to that of patients with more proximal clots.

Extended non-vitamin K antagonist oral anticoagulation therapy for prevention of recurrent venous thromboembolism.

Evidence from the use of traditional therapy (low-molecular-weight heparin/vitamin K antagonists) for venous thromboembolism (VTE) treatment and prevention suggests that extending treatment beyond the acute phase reduces recurrence. More recently, several non-vitamin K antagonist oral anticoagulants (NOACs) have been approved in the acute setting; accumulating evidence suggests continuing treatment with these agents beyond 12months offers additional benefits to patients with VTE. This review examines the evidence for NOAC use in longer-duration anticoagulation treatment, and discusses guidelines from major societies. Clinical data from the phase III extension studies for apixaban, dabigatran and rivaroxaban are presented, and the clinical and economic costs and benefits are examined. Evidence from other therapy areas utilising extended treatment regimens highlights the possible impact of factors relevant to extended anticoagulation therapy. Phase IV studies of NOACs are presented. US and European guidelines advise long-term therapy in certain instances, taking into account evidence on NOAC use in VTE accumulated recently. They support NOAC use where they have been selected as the initial therapy choice and therapy needs to be extended beyond 3months. The phase III extension studies demonstrate the benefits of extended NOAC use versus treatment cessation, with reduced recurrence rates versus placebo, although associated with a potential moderate increase in bleeding risk. Phase IV data are also emerging, with the recent XALIA study showing that a broad range of patients with VTE can benefit from continued rivaroxaban treatment; ongoing research will yield data on long-term use of the other NOACs in routine clinical practice.