Direct oral anti-coagulants compared with vitamin-K inhibitors and low-molecular-weight-heparin for the prevention of venous thromboembolism in patients with cancer: A meta-analysis study

Background: Prior meta-analysis studies showed that direct oral anticoagulants (DOAs) are as effective and safe as warfarin for the prevention of recurrences in patients with venous thrombo-embolism(VTE) and cancer. However, randomized studies also showed that low-molecular-weight-heparin (LMWH) performs better than warfarin in subjects with cancer. We therefore aimed to assess whether, even after pooling data with warfarin and LMWH, the use of DOAs remains safe and effective. Methods: We performed a meta-analysis of randomized controlled trials with the aim of assessing the efficacy and safety of DOAs in patients with VTE and cancer. Data on recurrent VTE and major and clinically relevant nonmajor bleeding were analyzed. Data were pooled and compared by ORs and 95% CIs. Results: Nine studies were included in the meta-analysis, seven in comparison with VKI, 2 with LMWH, accounting for a total of 1952 patients. VTE recurred in 5.4% and in 5.9% of patients with cancer treated with DOAs and conventional treatment, respectively (OR 0.79; 95% CI, 0.53-1.17; I2 0%). Bleeding occurred in 10.8% and 11% of patients receiving DOAs and conventional treatment, respectively (OR 0.96; 95% CI, 0.71-1.30; I2, 44%). Higher bleeding rates were found when DOAs are compared with LMWH (OR 2.72, 95% CI, 1.05-7.01). Conclusions: DOAs seem to be as effective and safe as conventional treatment for the prevention of VTE in patients with cancer in comparison with VKI. Higher bleeding rates were found when DOAs are compared with LMWH.