Background Cancer is a strong risk factor for development of venous thromboembolism (VTE), and VTE is a common cause of morbidity and mortality in cancer patients. Choice of optimal anticoagulant is complex. Low molecular weight heparin (LMWH) has been standard of care, however randomised data confirms direct oral anticoagulants (DOACs) non-inferior in prevention of recurrent VTE. Evolving evidence means that there are wide variations in current practice.
Aim To investigate management of VTE in oncology outpatients at a tertiary hospital, by examining drug choice, duration of treatment, and rate of bleeding events, to provide data around local practices and compare to current guidelines.
Methods Patients were identified via the outpatient adult oncology referrals database. Any patient commenced on systemic cancer therapy was included. Data was collected via retrospective case note analysis and analysed using Microsoft Excel.
Results In 2018, 315 patients were commenced on systemic cancer therapy, and 14% developed a VTE during treatment (52% with pulmonary embolism). The majority were symptomatic at presentation. 77% of patients were initially managed with LMWH, 20% were managed with a DOAC, and one patient was managed with a heparin infusion. 56% of patients initially managed with LMWH were switched to a DOAC at some point. Duration of treatment was highly variable. A low rate of bleeding was observed.
Discussion Incidence of VTE observed was similar to the literature. The majority of patients were still initially managed with LMWH. DOACs were generally used appropriately, however four patients with upper gastrointestinal cancer were treated with a DOAC, despite current recommendations to avoid. Due to hospital formulary restrictions, the DOAC prescribed was apixaban, despite evidence for its use not being published until 2020. Overall, management of VTE was variable and further research is likely needed to establish best practice in this complex patient group.