Cancer-associated thrombosis (CAT) carries significant morbidity and mortality. Low-molecular-weight heparin (LMWH) remains the standard of care, with recent systematic studies suggesting the efficacy and safety of rivaroxaban in the treatment of CAT. Uncertainty, however, remains regarding rivaroxaban efficacy and safety in real-world settings. We performed a systematic review and meta-analysis of studies comparing rivaroxaban to LMWH. We searched PubMed, MEDLINE, and EMBASE. The primary outcome was the net clinical benefit (NCB), while rates of major bleeding (MB), venous thromboembolism (VTE), clinically relevant nonmajor bleeding (CRNMB), and all-cause mortality events were secondary outcomes. Seventeen studies were included in the final analysis. Rivaroxaban had a better NCB (relative risk [RR] = 0.82; 95% CI = 0.75-0.89, Q = 10.51, I 2 = 0%), less VTE events (RR = 0.73, 95% CI = 0.65-0.82, Q = 6.76, I 2 = 0%), and lower all-cause mortality (RR = 0.72, 95% CI = 0.57-0.91, Q = 32.8, I 2 = 79%) compared to LMWH. Additionally, comparable MB events (RR = 1.07, 95% CI = 0.85-1.33, Q = 16.9, I 2 = 11%). However, CRNMB events were higher in the rivaroxaban group (RR = 2.02, 95% CI = 1.46-2.80, Q = 9.9, I 2 = 19%). Additional analyses demonstrated consistency of results. Our review encompassing data from randomized and real-world data suggested rivaroxaban superiority compared to LMWH in terms of a better NCB, fewer VTE events, lower all-cause mortality, and comparable MB risk while carrying a higher risk of CRNMB. These findings support the use of rivaroxaban in the treatment of CAT. Additionally, it warrants a sizable randomized controlled study testing the superiority of rivaroxaban versus LMWH formulation and ascertaining bleeding outcomes according to cancer type and site.
Keywords: CAT; DOAC; NOAC; cancer-associated thrombosis; malignancy.