Clinical question: Are direct oral anticoagulants (DOACs) a suitable alternative to low molecular weight heparin (LMWH) for treatment of venous thromboembolism (VTE) in patients with underlying malignancy?
Background: VTE is a frequent occurrence in patients with cancer. Although LMWH has previously been considered the standard of care, recent studies aim to compare the efficacy and safety profiles of DOACs to those of LMWH.
Study design: Meta-analysis of randomized controlled trials.
Setting: Literature search of PubMed, Embase, and the Cochrane Collaboration Central Register of Controlled Trials.
Synopsis: The authors identified four randomized controlled trials (RCTs) with a total of 2,907 participants who met their inclusion criteria: comparing DOACs to LMWH in cancer patients with therapy of at least six months. DOACs were associated with a significant reduction of VTE recurrence compared to LMWH (risk ratio 0.62; 95% confidence interval 0.44-0.87). However, the risk of clinically relevant non-major bleeding (CRNMB) was increased with the use of DOACs (RR 1.58; 95% CI 1.11-2.24). There was no significant difference in the risk of major bleeding (RR 1.33, 95% CI: 0.84-2.1) and overall mortality (RR 0.99, 95% CI: 0.84-1.17) between DOACs and LMWH. A subgroup analysis of major bleeding by cancer type found increased major bleeding with DOACs in patients with gastrointestinal cancer. Further studies directly comparing the efficacy and safety of different DOACs are needed.
Bottom line: DOACs may be an appropriate substitute for LMWH in patients with VTE and underlying malignancy, but caution should be used in patients with gastrointestinal cancer.
Citation: Haykal T et al. Direct oral anticoagulant versus low-molecular-weight heparin for treatment of venous thromboembolism in cancer patients: An updated meta-analysis of randomized controlled trials. Thromb Res. 2020;194:57-65. doi:10.1016/j.thromres.2020.06.025.
Dr. Bogard is an assistant professor of medicine, division of hospital medicine, at the Emory School of Medicine, Atlanta.