Management of Recurrent Venous Thromboembolism During Anticoagulant Treatment in Cancer Patients - a Prospective Cohort Study

Inclusion Criteria: * Documented active cancer (i.e. diagnosis of cancer within the past 6 months; recurrent, regionally advanced, or metastatic disease; currently receiving treatment or received treatment within the past 6 months) * Objectively confirmed symptomatic or incidental recurrent VTE while on anticoagulant therapy. The previous VTE and index recurrent VTE will include symptomatic or incidentally detected proximal deep vein thrombosis (DVT) of the lower extremities; symptomatic proximal upper extremity DVT (either related to a catheter or not); symptomatic distal DVT; symptomatic or incidentally detected multiple subsegmental, segmental or more proximal pulmonary embolism (PE). Exclusion Criteria: A potential subject who meets any of the following criteria will be excluded from participation in this study: * Use of thrombolysis * Anticoagulant treatment for the recurrent VTE for longer than 72 hours * Treatment with fondaparinux, unfractionated heparin, prophylactic doses of LMWH, or VKAs at time of recurrent VTE * Acute hepatitis, chronic active hepatitis, or severe hepatic dysfunction (Child Pugh C or \<MELD \> 10) * Active bleeding * Recent major surgery (\<2 weeks or longer, if still at high risk for bleeding) * Uncontrolled hypertension (systolic arterial pressure \>160 mmHg) * Known bleeding diathesis * Platelet count \<50.000 mm3 * Creatinine clearance \<30 mL/min (Cockcroft-Gault formula) * Life expectancy of less than 1 month * Dual antiplatelet therapy or aspirin at doses ≥165 mg daily * Current diagnosis or history of heparin-induced thrombocytopenia * Any condition, which in the opinion of the investigator, would put the subject at an unacceptable risk from participating in the study. * Suspected non-compliance at the time of recurrent VTE