Systematic Review and Meta-Analysis of Real-World Studies Evaluating Rivaroxaban for Cancer-Associated Venous Thrombosis

IntroductionWhile not designated as guideline-recommended first-line anticoagulation therapy, about one in five patients in the United States receive rivaroxaban for the treatment of cancer-associated venous thrombosis (CAT). MethodsA systematic review and meta-analysis were performed to evaluate the incidences of recurrent venous thromboembolism (VTE), major bleeding, and all-cause mortality in rivaroxaban patients treated for CAT in routine practice. Literature searches of MEDLINE and SCOPUS were performed through September 2017 to identify real-world studies of 20 patients evaluating the incidence of recurrent VTE, major bleeding, or all-cause mortality in CAT patients anticoagulated with rivaroxaban. Using a Hartung-Knapp random-effects model, the pooled incidence estimates and 95% confidence intervals (CIs) were calculated for each end point. ResultsSix studies evaluating rivaroxaban for CAT were identified. Of these, three were prospective and three were retrospective. Study sample sizes ranged from 41 to 949 patients, and duration of follow-up ranged from 164 to 496 days. The most frequent active cancer sites reported in studies were gastrointestinal (range: 12.0-56.0%), genitourinary (range: 8.6-26.0%), and breast (range: 9.3-25.5%). The weighted average incidences of recurrent VTE, major bleeding, and all-cause mortality were 4.2% (95% CI = 2.6-6.6%; I-2 = 31%), 2.9% (95% CI = 1.6-5.0%; I-2 = 59%), and 16.1% (95% CI = 6.0-36.6%; I-2 = 96%). ConclusionsThis meta-analysis suggests that incidences of recurrent VTE and major bleeding among rivaroxaban-managed patients are not dissimilar to those seen in recent randomized trials of anticoagulation in CAT. The pooled incidence for mortality was lower than reported in many anticoagulation CAT trials. This may suggest that rivaroxaban is being used in CAT patients who have less severe cancer.