Antithrombotic therapy and survival in cancer patients.

Venous thromboembolism is a common complication in patients with malignant disease. The development of symptomatic thromboembolism is associated with a poor prognosis for patients with cancer. Retrospective analysis of studies comparing unfractionated heparin with low-molecular-weight heparin (LMWH) for the initial treatment of deep vein thrombosis indicated improved survival for cancer patients receiving LMWH therapy. Prospective studies exposing cancer patients to LMWH therapy, in the absence of established thrombosis, suggest that survival may be prolonged in these patients after LMWH exposure. Ongoing studies, with careful attention to distribution of prognostic variables for cancer outcome, will help to answer the question regarding whether LMWH may indeed be used for this indication.