Study Finds Direct Oral Anticoagulants Significantly Decrease Recurrent Venous Thrombosis for Adult Patients With Cancer

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Direct oral anticoagulants should be considered the standard of care to treat adult patients with cancer-associated thrombosis, according to a new, ongoing study by Mayo Clinic researchers published by Riaz et al in Mayo Clinic Proceedings. The report examined the results of four randomized clinical trials involving 2,894 patients and found that direct oral anticoagulants significantly decreased cancer-associated venous thrombosis recurrence without significantly increasing bleeding compared with parenteral dalteparin.

Thrombotic outcomes increase mortality in patients with cancer and are the second most common cause of death after disease progression.

"Our meta-analysis [found that patients with cancer] who experience acute venous thrombosis events and were treated with direct oral anticoagulants experienced a 41% decrease in the rate of thrombosis recurrence compared with dalteparin, without significantly increasing major bleeding," said co–first study author Irbaz Riaz, MBBS, a Mayo Clinic hematologist and oncologist.

Direct comparisons showed that direct oral anticoagulants significantly decreased recurrent venous thromboembolism events compared with dalteparin (odds ratio [OR] = 0.59, 95% confidence interval [CI] = 0.41–0.86, I2 = 25%) without significantly increasing major bleeding (OR = 1.34, 95% CI = 0.83–2.18, I2 = 28%).

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Mixed treatment comparisons showed that apixaban and rivaroxaban significantly decreased venous thromboembolism recurrent events compared with dalteparin. Edoxaban significantly increased major bleeding compared with dalteparin, and rivaroxaban significantly increased clinically relevant nonmajor bleeding compared with dalteparin and other direct oral anticoagulants.

Direct oral anticoagulants have been considered the standard of care to treat venous thrombosis in patients without cancer. "This analysis indicates the same is true for patients with cancer," said Robert McBane II, MD, a Mayo Clinic cardiologist and the study's senior author. The systematic review led by Mayo Clinic, which also involved researchers from five other institutions, did not find differences in mortality based on the use of oral anticoagulants vs dalteparin. The authors recommended caution in using anticoagulants when treating patients at high risk of bleeding.

The researchers used a novel framework for a "living," interactive review of randomized controlled trials, beginning in September 2019. Results will be updated as more information becomes available.

"We have created interactive evidence summaries of multiple treatment options that present the benefits and harms, and evidence certainty for outcomes, and this evidence is updated as soon as new studies are published," explained M. Hassan Murad, MD, a Mayo Clinic clinical epidemiologist who leads Mayo Clinic's Evidence-Based Practice Research Program and is the study's corresponding author. "We will continue to add randomized controlled trials to this 'living' research, leading to more discoveries that produce improved outcomes for patients."

The study authors concluded, “Direct oral anticoagulants should be considered a standard of care for the treatment of cancer-associated thrombosis except in patients with a high risk of bleeding. Current evidence favors the use of apixaban for the treatment of cancer-associated thrombosis among other direct oral anticoagulants.”

Disclosure: For full disclosures of the study authors, visit

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.