A ten-year comparison of treatment and outcomes of cancer-associated thrombosis to non-cancer venous thromboembolism: from traditional anticoagulants to direct oral anticoagulants.

ABSTRACT

DOACs have emerged as first-line treatment in most cancer-associated thrombosis (CAT), representing a paradigm shift in its management. However, CAT management remains challenging and requires careful risk-benefit considerations. A retrospective analysis of CAT presentations to a tertiary referral centre from January 2011 to December 2020. Outcomes in CAT patients were compared to VTE patients without malignancy. Subgroup analysis was also conducted for CAT according to anticoagulation type. 514 CAT cases from 491 patients were identified from 3230 total VTE cases. CAT patients had higher rates of major VTE (PE and/or proximal DVT) compared to patients without malignancy (78.4% vs. 66.8%, p < 0.001). CAT patients also had higher rates of VTE recurrence (HR 1.66, 95%CI 1.23-2.26), major bleeding (HR 3.41, 95%CI 2.36-4.93), VTE-related mortality (HR 2.59, 95%CI 1.46-4.62) and bleeding-related mortality (HR 2.66, 95%CI 1.05-6.73). There were no significant differences in rates of VTE recurrence, major bleeding, VTE-related mortality or fatal bleeding between CAT patients treated with DOACs, enoxaparin or warfarin. In the subgroup of CAT treated with DOACs, there was no significant difference in rates of GI bleeding compared to the enoxaparin subgroup (HR 0.17, 95%CI 0.02-1.26). CAT was associated with a larger clot burden and higher rates of VTE recurrence, major bleeding and mortality compared to VTE patients without malignancy in this large real-world study. This study demonstrated no significant differences in complication rates for CAT patients treated with DOACs over enoxaparin, suggesting that DOACs can be safely used in most cases of CAT.