Direct oral anticoagulants for thromboprophylaxis in ambulatory patients with cancer

Background: Venous thromboembolism (VTE) is a common complication in cancer patients. We aim to evaluate the effect and safety of direct oral anticoagulants (DOACs) as primary prophylaxis in ambulatory cancer patients.Methods: We conducted a literature search in PubMed, EMBASE and ClinicalTrials for studies that evaluated DOACs for thromboprophylaxis in cancer patients. RevMan 5.3 software was used for this meta-analysis.Results: Three randomized controlled trials (RCTs) with a total of 1465 patients were pooled in the meta-analysis. DOACs significantly reduced the symptomatic VTE incidence during intervention period (RR 0.23, CI 0.11-0.47, P<0.0001, I=9%). Significantly lower total VTE incidence (RR 0.53, CI 0.36-0.78, P = 0.001, I =30%) and PE incidence (RR 0.50, CI 0.28-0.89, P = 0.02, I =5%) were found during the observation period, and a trend for less symptomatic DVT events was found in the DOACs group (RR 0.62, CI 0.37-1.04, P = 0.07, I =5%). No differences for all-cause mortality were found between groups (RR 0.92, CI 0.74-1.15, P = 0.47, I =14%). DOACs did not significantly increase major bleeding risks (RR 1.66, CI 0.72-3.83, P = 0.24, I =0%) during the intervention period or clinically relevant non-major bleeding events (RR 1.50, CI 0.90-2.49, P = 0.12, I =0%) and total bleeding events during the observation period (RR 1.50, CI 0.98-2.29, P = 0.06, I =0%).Conclusion: DOACs are effective for thromboprophylaxis in ambulatory cancer patients, but there is a potential risk of bleeding. DOACs may be recommended in selected patients at high risk of VTE. More high-quality studies are needed to further validate our results.Abbreviations: CAT: cancer-associated thrombosis; CI: confidence interval; DOAC: direct oral anticoagulant; DVT: deep vein thrombosis; LMWH: low molecular weight heparin; NNH: number needed to harm; NNT: number needed to treat; PE: pulmonary embolism; RCT: randomized controlled trials; RR: risk ratio; RD: rate difference; VTE: venous thromboembolism.