A double-blind placebo-controlled randomized study on the efficacy and safety of enoxaparin for the prevention of upper limb deep vein thrombosis in cancer patients with central vein catheter

Abstract number: P0825

Verso M., Agnelli G., Bertoglio S., Di Somma C., Paoletti F., Ageno W., Bazzan M., Parise P., Quintavalla R., Naglieri E., Santoro A., Imberti D., Sorarù M.

Italy

Background  

Upper limb deep vein thrombosis (UL-DVT) is an emerging clinical problem in cancer patients with central vein catheter (CVC). The efficacy of prophylaxis for CVC-related UL-DVT with low fixed dose of warfarin or low molecular weight heparin has been claimed based on open studies with limited sample size. The rate of bleeding complications in cancer patients undergoing prolonged anti-thrombotic prophylaxis is unclear.

Aim of the study  

To assess the efficacy and safety of enoxaparin in the prevention of UL-DVT in cancer patients with CVC.

Study design and methods  

Ethics was a multicenter double-blind randomized placebo-controlled study in 11 Italian centers. Enoxaparin, 40 mg once a day, or an identical placebo were given subcutaneously for 6 weeks, starting 2 h before the insertion of the CVC. Consecutive patients with a silicon or II generation poliurethane CVC to be used for chemotherapy were included in the study. The primary endpoints of the study were UL-DVT, as confirmed by venography (CVC limb) performed 6 weeks after randomization, or earlier in case of clinical suspicion of DVT or compulsory catheter removal and/or clinically overt PE confirmed by objective testing. All randomized patients were followed up for a 3-month after venography. The safety endpoint was major bleeding. The analysis of the study was done in an ‘intention-to-treat’ bases. The incidence of VTE in the placebo group was postulated to be >30% and that of enoxaparin 15%. With an a = 0.05 and a power of 0.80, two-sided test, 300 evaluable patients were required. To ensure this number with an expected evaluability rate of 75%, an overall randomization of 400 patients was assumed to be needed.

Study status  

Currently 360 patients were enrolled in the study. The final efficacy and safety results will be available for presentation in July 2003.