Abstract
BACKGROUND: Cancer-associated thrombosis (CAT) is one of the major complications during the treatment course of cancer, which often challenges clinicians in daily clinical practice despite anticoagulation therapy. CASE SUMMARY: A 57-year-old man with a history of a liver transplantation was diagnosed with post-transplant lymphoproliferative disorders. He developed severe systemic thromboses including a massive pulmonary embolism and was treated with anticoagulation therapy including a factor Xa inhibitor. However, the systemic thromboses worsened despite the anticoagulation therapy. During the acute treatment course of the thromboses, we administered anticancer drug therapy in hopes of an improvement in the activity of the cancer status leading to a favourable effect on the thrombosis status. Multi-disciplinary treatment including anticoagulation therapy and anticancer drug therapy successfully improved the systemic thrombosis. DISCUSSION: Anticoagulation therapy is a standard treatment for CAT; however, some cases of CAT do not successfully improve despite anticoagulation therapy, partly due to a highly active cancer status. Anticancer drug therapy might increase the risk of a thrombosis, whereas it could improve the activity of the cancer status leading to a decreased risk of a thrombosis. A multi-disciplinary therapy might be a reasonable option especially for CAT with a highly active cancer status.