Direct Oral Anticoagulants Versus Low-molecular-weight Heparins for the Treatment of Acute Venous Thromboembolism in Patients with Gastrointestinal Cancer: a Systematic Review and Meta-analysis

Background: The association between gastrointestinal (GI) cancer and a high incidence of venous thromboembolism (VTE) is well known. Previous randomized controlled studies demonstrated that direct oral anticoagulants (DOACs) effectively treat cancer-associated thrombosis (CAT). However, some DOACs appeared to increase the risk of bleeding, particularly in patients with GI malignancies. Therefore, the current systematic review and meta-analysis were conducted to evaluate the safety and efficacy of DOACs in GI cancer-associated thrombosis.

Methods: Two investigators individually reviewed all studies that compared DOACs and low-molecular-weight heparins (LMWHs) in GI cancer-associated thrombosis and were published in MEDLINE and EMBASE before February 2022. The effect estimates and 95% confidence intervals (CIs) from each eligible study were combined using the Mantel-Haenszel method.

Results: A total of 2226 patients were included in the meta-analysis. The rates of major bleeding in the DOAC and LMWH groups were not significantly different (relative risk [RR]: 1.31; 95% CI: 0.84-2.04; P = 0.23; I = 41%). However, the rate of clinically relevant nonmajor bleeding (CRNMB) was significantly higher in the DOAC group (RR: 1.76; 95% CI: 1.24-2.52; P = 0.002; I = 8%). The risks of recurrent VTE in the groups did not significantly differ (RR: 0.72; 95% CI: 0.49-1.04; P = 0.08; I = 0%).

Conclusions: The current data suggest that treatment of GI cancer-associated thrombosis with DOACs significantly increases the risk of CRNMB. However, the risk of major bleeding was not significantly different. The efficacy of DOACs for preventing recurrent VTE in GI cancer was comparable to that of LMWHs.

Trial Registration: INPLASY202180113 .