Cancer-associated thrombosis: enhanced awareness and pathophysiologic complexity

Thrombosis, both venous and arterial, is a leading cause of morbidity and mortality in patients with cancer. Studies on the molecular basis of cancer-associated thrombophilia have a long story starting from the first observation of the presence of tumor cells in circulating microthrombi 2 centuries ago. The profound link between pathways of blood coagulation and tumor biology has been more and more unraveled, and new actors in this complex interaction have been identified. The unfavorable impact of thrombosis in a patient with cancer, on which also hangs a high bleeding risk as compared to the noncancer population, has led during years to the production of large clinical studies to adopt the best prophylaxis and treatment strategies of venous thromboembolism in different medical and surgical settings, now incorporated in dedicated international guidelines. This field, however, still represents an open challenge due to the intrinsic variability of the patient with cancer with his/her personal medical history and cardiovascular risk factors, as well as the type, site and stage of the tumor, and the use of a wide array of new sophisticated anticancer drugs. This review aims to highlight some of the many key observations in the field of cancer and thrombosis, spanning the scope from fundamental tumor biology to advanced clinical trials of new anticoagulants. We hope that some of the examples we have included will inspire readers to explore and discuss these topics, thereby increasing awareness of cancer-related thrombosis in both physicians and patients.