The increased risk of thrombosis associated with cancer has been known since Trousseau's observations in the 19th century. Roughly 15 to 20 years ago, studies found that patients with cancer and thrombosis had a higher likelihood of recurrent thrombosis despite the use of anticoagulation, and an increased risk of bleeding with anticoagulation, than patients without cancer [1]. At that time, cancer treatments were limited to combinations of surgery and radiation, and conventional chemotherapy with regimens comprised of chemical agents that impaired cell replication in an indiscriminate manner.
