New research encourages changes in the treatment and prevention of deep vein thrombosis in cancer patients

Researchers at The University of Texas M.D. Anderson Cancer Center report that optimizing the use of anticoagulants in cancer patients with deep vein thrombosis could improve outcomes, reduce hospital stay and lower the cost of treatment. The study which gathered data from 529 cancer patients with deep vein thrombosis, and which represents the most comprehensive study of it kind, suggests that bleeding in treated patients and the reoccurrence of thrombosis is higher than previously reported. Furthermore the hospital stay time and associated costs are particularly high in cancer patients admitted for deep vein thrombosis. One of the major conclusions of the study is that greater use of low molecular weight heparin in an out-patients setting could considerably reduce the cost of treating cancer patients with deep vein thrombosis and shorten the time that they must stay in hospital. A second recent report suggests that the situation could be further improved through greater use of thromboprophylaxis.

DailyUpdates 3rd September, 2004: Deep vein thrombosis is a particularly serious condition due to the associated high risk of pulmonary embolism. This thromboembolic disease is common in elderly hospitalized patients and those who have had recent surgery. The incidence of deep vein thrombosis is also especially high in patients with cancer.

It is expected that 1.3 million new cases of cancer will be diagnosed this year in the US alone and over 0.5 million deaths resulting from cancer are expected. Epidemiology data identifies thrombosis as the second leading cause of mortality in cancer patients following the disease itself. Chemotherapy appears to represent a strong risk factor for developing deep vein thrombosis. Likewise thrombotic disease is also associated with advanced malignancy as well as renal, pancreatic, gastric and brain tumors. A recent evaluation of historical data has shown that compared to patients without cancer, the recurrence of thromboembolic disease and death in patients with deep vein thrombosis is increased by more than three-fold with concurrent malignancy. Some experts have therefore suggested that cancer patients should be approached as a distinct patient group in terms of treatment for thromboembolic disease. However better characterization of the disease process in cancer patients is required to best improve treatment options.

In a paper published in the August edition of the journal Archives of Internal Medicine, Linda Elting and colleagues from The University of Texas M.D. Anderson Cancer Center report on the largest study to date of the outcomes and associated costs of deep vein thrombosis treatment in cancer patients . In contrast to many studies this one was restricted to cancer patients and is therefore important since it will more precisely define risks, costs and treatment practices in this particular cohort.

Of the patients presenting with deep vein thrombosis 87% experienced complete or partial resolution following treatment. Resolution was more limited in patients with poor mobility or status and those whose cancers were progressing under treatment. Low molecular weight heparin was the most effective anticoagulant for producing resolution. The report also found that although deep vein thrombosis was rarely fatal in cancer patients, causing death in only 2% of patients, complications were common, occurring in almost 20% of patients. Bleeding was a particularly common complication with 12% of patients hemorrhaging following anticoagulation treatment. Likewise recurrence of deep vein thrombosis was also common, also observed in around 20% of patients. Recurrence was most frequently a complication in patients with inferior vena cava filters implanted to prevent pulmonary embolism.

The study also reported the costs of treating deep vein thrombosis in patients with cancer. The authors estimate that in 2000 the average cost of treating a thromboembolic event was $11,000 in the general population. This figure was well over 50% higher in cancer patients. The increased cost was due both to increased hospital stay and an increased incidence of bleeding. Although the authors suggest that it will be difficult to reduce the increased incidence of bleeding the use of anticoagulants in an outpatient setting in uncomplicated patients should reduce hospital stay. The majority of the patients in the present study were treated with unfractionated heparin which requires a prolonged infusion and hence an extended hospital stay. In contrast low molecular weight heparin can be administrated as a single subcutaneous injection and has been shown to successfully treat deep vein thrombosis in cancer patients. In the general population low molecular weight heparin is increasingly being used in patients with uncomplicated disease and can reduce hospital stay times by 50%.

According to pharmaceutical analysts the treatment of conditions associated with cancer represents an unmet market. The treatment of cancer pain is one area that is receiving increasing interest (click here for an analysis of this field). Likewise more effective treatment of deep vein thrombosis is also required. The present study represents one of the most in depth insights into deep vein thrombosis in patients with cancer and the results support changes in treatment practice. In particular increased use of low molecular weight heparin in an out-patient setting is encouraged to reduce hospital stay and costs and possibly to increase resolution of thrombotic events. The shift towards greater out-patient treatment of deep vein thrombosis in cancer patients is already evident in specialist oncology centers.

Analysts have also suggested that the prophylactic use of new oral anticoagulants, such as AstraZeneca's Exanta may further improve the treatment of deep vein thrombosis (click here for more on prophylactic use of anticoagulants). This concept is receiving considerable attention, particularly following the publication of the PREVENT trial in last month's edition of the journal Circulation. This study demonstrated that the prophylactic administration of dalteparin daily for 14 days produced a 45% reduction in the development of deep vein thrombosis. There was no significant increase in major bleeding. Data evaluating the prophylactic use of anticoagulants specifically in cancer patients is not yet available. It is hoped that this issue will soon be addressed due to the potential benefit that such clinical practices may offer cancer patients.

Source: Outcomes and cost of deep venous thrombosis among patients with cancer. Arch Intern Med. 2004 Aug 9-23;164(15):1653-61

This article is highlighted in the September 3rd edition of DailyUpdates-Cardiovascular Disorders, LeadDiscovery’s unique bulletin of breaking journal articles and press releases for the drug discovery community. To access the article and to view today’s bulletin click here