Preventing clot recurrence in cancer patients: heparin vs warfarin

7 Dec 2014

Deep-vein thrombosis presents a significant challenge for cancer patients and their physicians. A new study confirms that patients getting low-molecular-weight heparin are better protected against clot recurrence compared to warfarin.

What is deep-vein thrombosis?

Deep-vein thrombosis, a blood clot that forms in a major vein of the leg or in the arms, pelvis, or other large veins in the body, as well as pulmonary embolism, a potentially deadly condition that occurs when the clot breaks off and travels to the lungs.

While current clinical practice guidelines recommend the use of low-molecular-weight heparins (LMWH) rather than warfarin to reduce this risk, recommendations were based largely on a single trial.

Given the lack of confirmatory trials or trials including different medications, warfarin remains a commonly used anticoagulant treatment in cancer patients.

CareAcross-thrombosis

Trial with 900 patients confirms benefits of low-molecular-weight heparins

To confirm previous findings that LMWH is superior to warfarin in preventing recurrent venous thromboembolism VTE among cancer patients, researchers enrolled 900 cancer patients with deep-vein thrombosis or pulmonary embolism in a randomized, Phase 3 trial evaluating the efficacy and safety of the LMWH tinzaparin.

Participants received either

  • tinzaparin once daily for six months or
  • tinzaparin once daily for five to 10 days followed by six months of warfarin.

During the treatment period, 31 patients (6.9%) treated with tinzaparin experienced recurrent VTE compared with 45 (10%) patients treated with warfarin.

While tinzaparin did not meet statistical significance in reducing recurrent VTE, the drug showed statistically significant activity in reducing recurrent deep-vein thrombosis in veins above the knee.

Side effects

Researchers did not observe a difference in the mortality or incidence of major bleeding events (2.9% in the tinzaparin arm and 2.7% in the warfarin arm), but noted that significantly fewer patients experienced clinically relevant, non-major bleeding with tinzaparin than warfarin (11% vs 16%).

“As the largest randomized, controlled trial on the treatment of thrombosis among cancer patients, this study reinforces clinical guidelines supporting the use of low-molecular-weight heparins instead of warfarin to prevent recurrent blood clots,” said lead study author Agnes Lee, MD, of the University of British Columbia in Vancouver, Canada.

 

Source: eCancer News
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