Among patients with a first episode of unprovoked venous thromboembolism (VTE), the contemporary one-year risk of detecting occult cancer is approximately 4% to 7%. Of these cases, 30% to 60% are missed by routine limited screening for cancer. RNA profiling of platelets is a promising, highly accurate biomarker for cancer detection, but its clinical utility in patients with unprovoked VTE is unknown. The objective of the present study is to evaluate the diagnostic accuracy of platelet RNA profiling in detecting occult cancer in patients with unprovoked venous thromboembolism. Secondary objectives include evaluation of other biomarkers for cancer, prediction of bleeding, and prediction of recurrent VTE.