What is select-d? 

Thrombosis or blood clots are a major problem facing people with cancer. It appears that cancer cells can release chemicals which make the blood ‘thicker’ than usual and therefore more likely to form a clot. A thrombosis may cause a red, painful, swollen leg or arm (a ‘deep vein thrombosis’ or DVT) or, if bits of the clot break off and are carried to the lungs, sudden onset of breathlessness, cough or chest pain (a ‘pulmonary embolus’ or PE). The clots require treatment as some may be life-threatening.

Advances have been made in developing new blood thinning treatments to treat blood clots, called anticoagulants. Standard treatment is with a daily injection under the skin of a blood thinning agent called dalteparin or ‘Fragmin’ which has been shown to have advantages over warfarin in patients with cancer who were treated for 6 months. Dalteparin helps to dissolve the clot and prevent others forming. A new blood thinning agent called rivaroxaban or ‘Xarelto’ has been used as an alternative to dalteparin in some research studies. Rivaroxaban has the advantage of being a tablet rather than an injection. Whether to stop or continue anticoagulation after 6 months, however, remains uncertain with no previous research studies having assessed this question in cancer patients to date. More research is needed on the effectiveness of rivaroxaban as it is not yet known whether dalteparin or rivaroxaban is better at treating and preventing clots in people with cancer or for how long the drugs should be taken (6 months or 12 months).

The purpose of the study is to find out whether rivaroxaban is as good as dalteparin at treating clots and preventing other clots from forming, and whether it is better to give anticoagulant treatment for 6 or 12 months.