Retrospective Review of Prescribing Patterns in Cancer-Associated Thrombosis: A Single Center Experience in Edmonton, Alberta, Canada

Low molecular weight heparin (LMWH) is the standard of care for treating cancer-associated thrombosis (CAT), although new evidence for direct oral anticoagulants (DOACs) supports use in specific cancer populations. In this retrospective review at a specialty CAT clinic from 2016 to 2019, we report the use of anticoagulants (LMWH, DOACs, warfarin, anticoagulant class change) in the acute and chronic phases of CAT and compare use before/after publication of the Hokusai-VTE Cancer trial. Death, venous thromboembolism (VTE) recurrence and bleeding was also reported. Of the 221 included, median age was 69 years, with 57.5% having metastatic disease. In the acute phase, 80.1% were prescribed LMWH, 4.1% DOAC, and 14.5% had an anticoagulant class change (LMWH to DOAC; 78.1%). In the chronic phase, 35.8% were prescribed LMWH, 11.3% DOAC, and 42.9% had an anticoagulant class change (LMWH to DOAC; 90.1%). Use of DOACs in the acute and chronic phase prior to the Hokusai-VTE trial was 1.0% and 2.0%, respectively, and following publication was 6.8% and 19.6%. Death occurred for 22.6% patients, recurrent VTE in 7.2%, and bleeding in 5.0%. DOAC use is increasing with time; real-world data may help to guide optimization of the care of complex patients.