Published online Oct 15, 2019. doi: 10.4251/wjgo.v11.i10.866
Peer-review started: February 27, 2019
First decision: July 31, 2019
Revised: September 3, 2019
Accepted: September 12, 2019
Article in press: September 12, 2019
Published online: October 15, 2019
Venous thromboembolism (VTE) is a common occurrence in cancer patients, specifically in those patients with advanced disease. The goal of anticoagulation therapy is to prevent VTE recurrence while mitigating the safety side effects of therapy, mainly major bleed (MB). Gastrointestinal (GI) cancers are associated with a high incidence of thromboembolic events and an even higher risk of bleeding events while on active chemotherapy. Recurrent VTE efficacy and MB safety complications due to secondary VTE prophylaxis remain a noticeable limitation in treating patients with cancer-associated VTE (CAVTE) with vitamin K antagonist and low molecular weight heparin (LMWH). Direct oral anticoagulants (DOACs), a newer set of agents with easier access and administration for CAVTE, have promising effectiveness outcomes although there is a safeness hesitance to utilize these agents in select subsets of high-risk cancer patients.
The current role of DOACs in cancer patients is still unfolding and current treatment guidelines recommend them as a preferred option. Since the advent of DOACs, our clinical practice has noticed an unusual safety profile often having to be addressed by changes in administration, holding of therapy, cessation of therapy or switching to another treatment regimen. We wanted to analyze the efficacy and safety outcome of our own institutional real-world experience with DOAC’s in the GI cancer setting.
The goal of our study was to evaluate our institutional outcomes of DOACs and LMWH in patients with active GICA-VTE at The University of Arizona Cancer Center based on safety and efficacy reported events.
Subjects were extracted from a retrospective chart review of GI cancer patients treated at our comprehensive cancer center for incidental or symptomatic VTE with either DOACs or LMWH. Outcomes events, recurrent VTE and MB, were recorded from patients with an active GI malignancy and concurrent anticoagulation therapy at and beyond 6 mo.
Patients on apixaban (n = 29), rivaroxaban (n = 37) and LMWH (n = 40) met inclusion criteria. Recurrent VTE at 6 mo was noted in 7.5% (n = 3), 6.8% (n = 2) and 2.7% (n = 1) of patients on LMWH, apixaban and rivaroxaban, respectively (all P= NS). MB at 6 mo was 5% (n = 2) for LMWH, 6.8% (n = 2) for apixaban and 21.6% (n = 8) for rivaroxaban (overall P = 0.048; vs LMWH P = 0.0423; all other P = NS). Beyond six-months, MB rates were 21% and 10% for DOACs and LMWH (P = NS), respectively, while maintaining efficacy. Significant predictors of any outcome for all anticoagulation therapies included: active systemic treatment (OR - 5.1, 95%CI: 1.3-19.3), high Khorana Score (≥ 3 points) (OR = 5.5, 95%CI: 1.7-17.1), active smoker (OR = 6.7, 95%CI: 2.1-21.0), pancreatic cancer (OR = 6.8, 95%CI: 1.9-23.2), and stage IV disease (OR = 9.9, 95%CI: 1.2-79.1).
Rivaroxaban compared to apixaban and LMWH had a significantly higher risk of major bleeding on GICA-VTE patients with equivocal efficacy.
Our study shows similar efficacy of LMWH as compared to apixaban and rivaroxaban. Nonetheless, the safety profiles of these new DOACs have to lead to the preferred use of apixaban, which had lower bleeding events in the high-risk GI cancer patient population.