The Role of Direct Oral Anticoagulants in the Treatment of Cancer-Associated Venous Thromboembolism: Review by Middle East and North African Experts.

ABSTRACT

Venous thromboembolism is a leading cause of morbidity and mortality in patients with active cancer who require anticoagulation treatment. Choice of anticoagulant is based on careful balancing of the risks and benefits of available classes of treatment vitamin K antagonists, low-molecular-weight heparin (LMWH), and direct oral anticoagulants (DOACs). Results from randomized controlled trials have shown the consistent efficacy of DOACs versus LMWH in the treatment of cancer-associated venous thromboembolism (VTE). However, increased major gastrointestinal bleeding was observed for edoxaban and rivaroxaban, but not apixaban, compared with LMWH dalteparin. Most guidelines recommend DOACs for the treatment of cancer-associated VTE in patients without gastrointestinal or genitourinary cancer, and with considerations for renal impairment and drug-drug interactions. These updates represent a major paradigm shift for clinicians in the Middle East and North Africa. The decision to prescribe a DOAC for a patient with cancer is not always straightforward, particularly in challenging subgroups of patients with an increased risk of bleeding. In patients with gastrointestinal malignancies who are at high risk of major gastrointestinal bleeds, apixaban may be the preferred DOAC; however, caution should be exercised if patients have upper or unresected lower gastrointestinal tumors. In patients with gastrointestinal malignancies and upper or unresected lower gastrointestinal tumors, LMWH may be preferred. Vitamin K antagonists should be used only when DOACs and LMWH are unavailable or unsuitable. In this review, we discuss the overall evidence for DOACs in the treatment of cancer-associated VTE and provide treatment suggestions for challenging subgroups of patients with cancer associated VTE.

Patients with cancer are at risk of blood clots forming in their veins, which can cause illness and death. To prevent such blood clots, most patients with cancer need anticoagulant therapy. There are three types of anticoagulants available for the treatment of cancer-associated blood clots in a vein, namely, vitamin K antagonists, low-molecular-weight heparin (LMWH), and direct oral anticoagulants (DOACs). Drug trials have shown that DOACs are more effective than LMWH; however, DOACs can have a greater risk of causing major gastrointestinal bleeding. Among DOACs, edoxaban and rivaroxaban are drugs associated with higher rates of gastrointestinal bleeding. Recently updated guidelines for doctors recommend that DOACs be used as the first treatment for patients with cancer at risk of blood clot formation in a vein. For doctors in the Middle East and North Africa, this new approach differs from existing practices. Notably, choosing a treatment also depends on the type of cancer, because gastrointestinal cancers and cancers of the genitals and urinary system have an especially high risk of gastrointestinal bleeding. The choice also depends on the presence of kidney problems, drug­drug interactions, and access to the drugs. Apixaban may be the preferred DOAC in patients with gastrointestinal cancer, but this drug should be used with care in patients with upper or unresected lower gastrointestinal tumors. For patients with upper or unresected lower gastrointestinal tumors, treatment with LMWH may be preferred. Vitamin K antagonists should be used only when DOACs and LMWH are unavailable or unsuitable.