Thromboprophylaxis for patients with cancer and central venous catheters: A systematic review and a meta-analysis

BACKGROUND. Central venous catheter (CVC) placement increases the risk of thrombosis and subsequent death in patients with cancer. The objective of this systematic review was to determine the efficacy and safety of anticoagulation in reducing mortality and thromboembolic events in cancer patients with a CVC. METHODS. The authors searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and ISI the Web of Science databases. They included randomized controlled trials in patients with cancer comparing unfractionated heparin (UFH), low-molecular-weight heparin (LMWH), vitamin K antagonists, fondaparinux, or ximelagatran with no intervention, placebo, or each other. The standard methods of the Cochrane Collaboration were used for the analyses. RESULTS. Of 3986 identified citations we included 9 randomized clinical trials, none of which evaluated fondaparinux or ximelagatran. Heparin therapy (UFH or LMWH) was associated with a trend toward a reduction in symptomatic deep venous thrombosis (DVT) (relative risk (RR), 0.43; 95% confidence interval (95% CI), 0.18-1.06), but there was no statistically significant effect on mortality (RR, 0.74; 95% CI, 0.40-1.36), infection (RR, 0.91; 95% CI, 0.36-2.28), major bleeding (RR, 0.68; 95% CI, 0.10-4.78), or thrombocytopenia (RR, 0.85; 95% CI, 0.49-1.46). The effect of warfarin on symptomatic DVT also was not statistically significant (RR, 0.62; 95% CI, 0.30-1.27). CONCLUSIONS. The balance of benefits and downsides of thromboprophylaxis in cancer patients with CVC are uncertain. Clinicians together with their patients must weigh these factors carefully when making decisions regarding thromboprophylaxis.