Abstract
This report describes the case of a 66-year-old man with non-small cell lung cancer and venous thromboembolism (VTE). Unfractionated heparin (UFH) was initially used to control VTE before chemotherapy. However, switching UFH to warfarin or edoxaban, a novel oral anticoagulant (NOAC), failed. Chemotherapy was then administered to control the tumor which was thought to have been the main cause of VTE, which had been treated by UFH. After tumor shrinkage was achieved by chemotherapy, we were able to successfully switch from UFH to edoxaban. Controlling the tumor size and activity enabled the use of edoxaban as maintenance therapy for VTE.