Warfarin thromboprophylaxis in cancer patients with central venous catheters (WARP) : an open-label randomised trial
WARP Collaborat Grp UK (Including: Young, Annie M., Billingham, Lucinda J., Begum, Gulnaz, Kerr, David J., Hughes, Ana I., Rea, Daniel W., Shepherd, Stephen, Stanley, Andrew, Sweeney, Ann, Wilde, Jonathan and Wheatley, Keith). (2009) Warfarin thromboprophylaxis in cancer patients with central venous catheters (WARP) : an open-label randomised trial. Lancet, Vol.373 (No.9663). pp. 567-574. ISSN 0140-6736Full text not available from this repository.
Official URL: http://dx.doi.org/10.1016/S0140-6736(09)60205-1
Background The role and dose of anticoagulants in thromboprophylaxis for patients with cancer receiving chemotherapy through central venous catheters (CVCs) is controversial. We therefore assessed whether warfarin reduces catheter-related thrombosis compared with no warfarin and whether the dose of warfarin determines the thromboprophylactic effect.
Methods In 68 clinical centres in the UK, we randomly assigned 1590 patients aged at least 16 years with cancer who were receiving chemotherapy through CVCs to no warfarin, fixed-dose warfarin 1 mg per day, or dose-adjusted warfarin per day to maintain an international normalised ratio between 1. 5 and 2. 0. Clinicians who were certain of the benefit of warfarin randomly assigned patients to fixed-dose or dose-adjusted warfarin groups. The primary outcome was the rate of radiologically proven, symptomatic catheter- related thrombosis. Analysis was by intention to treat. This trial is 14 registered as an International Standard Randomised Controlled Trial, number I SRCTN 50312145.
Findings Compared with no warfarin (n=404), warfarin (n=408; 324 [79%] on fixed-dose and 84 [21%] on dose-adjusted) did not reduce the rate of catheter- related thromboses (24 [6%] vs 24 [6%]; relative risk 0 . 99, 95% Cl 0 . 57-1.72, p=0 . 98). However, compared with fixed-dose warfarin (n=471), dose-adjusted warfarin (n=473) was superior in the prevention of catheter- related thromboses (13 [3%] vs 34 [7%]; 0 . 38, 0.20-0.71, p=0 . 002). Major bleeding events were rare; an excess was noted with warfarin compared with no warfarin (7 vs 1, p=0. 07) and with dose-adjusted warfarin compared with fixed-dose warfarin (16 vs 7, p=0.09). A combined endpoint of thromboses and major bleeding showed no difference between comparisons. We did not note a survival benefit in either comparison.
Interpretation The findings show that prophylactic warfarin compared with no warfarin is not associated with a reduction in symptomatic catheter- related or other thromboses in patients with cancer and therefore we should consider newer treatments.
Funding Medical Research Council and Cancer Research UK.
|Item Type:||Journal Article|
|Subjects:||R Medicine > RC Internal medicine > RC0254 Neoplasms. Tumors. Oncology (including Cancer)|
|Divisions:||Faculty of Medicine > Warwick Medical School > Health Sciences
Faculty of Medicine > Warwick Medical School
|Library of Congress Subject Headings (LCSH):||Warfarin, Catheterization -- Complications, Thromboembolism, Cancer -- Treatment -- Complications|
|Journal or Publication Title:||Lancet|
|Publisher:||The Lancet Publishing Group|
|Official Date:||14 February 2009|
|Number of Pages:||8|
|Page Range:||pp. 567-574|
|Access rights to Published version:||Restricted or Subscription Access|
|Funder:||Medical Research Council (Great Britain) (MRC), Cancer Research UK (CRUK)|
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