Venous Thromboembolism Outcomes Among Cancer and Non-Cancer Patients Managed with Patient-Centric Guideline-Driven Protocol

Purpose/Introduction: Patients with cancer and venous thromboembolism (VTE) have higher complication rates including thrombosis recurrence and bleeding. Real world prospective clinical outcome estimates of VTE management comparing cancer and non-cancer patients are limited. To assess VTE recurrence, major bleeding, and clinically relevant non-major bleeding (CRNMB) in patients with cancer and without cancer, the prospective Mayo Clinic Thrombophilia Clinic Registry was analyzed.

Methods: Upon recruitment, consecutive patients with confirmed acute VTE (03/01/2013 - 04/30/2023) were treated in a standardized, guideline-sanctioned, protocol driven strategy incorporating shared patient-decision making. Patients were divided into groups based on cancer status. After enrollment, patients were actively followed at 3 month intervals, in person whenever feasible, by mailed questionnaire or scripted phone interview to assess vital status, medication compliance, VTE recurrence, major bleeding and CRNMB.

Results: Over the study time-frame, 2,064 patients (53.8% male, 46.2% female) with a cancer and 2,647 patients (54.9% male, 45.1% female) without cancer were enrolled. The most common cancers were gastrointestinal (n=423, 20.5%), pancreatic (n=287, 13.9%), genitourinary (n=198, 9.6%), hematologic (n=171, 8.3%), and lung cancer (n=170, 8.2%). Patients with cancer were older, had lower weight and lower platelet counts compared to non-cancer patients (Table1). Pulmonary embolism (PE, 52.6% vs 43.7%, p<0.001), upper extremity DVT (9.1% vs 6.0%, p<0.001), and splanchnic DVT (11.1% vs 6.9%, p<0.001) were more frequent among cancer patients. In contrast, leg DVT was more frequent among non-cancer patients (65.4% vs.47.2%, p<0.001). While mean duration of anticoagulation was similar between groups, notable differences in 3 month and > 9 month durations were evident as were initial anticoagulant choices (Table 1). Despite a well-organized protocol driven and guideline sanctioned management strategy, patients with active cancer experienced a 2.2-fold higher rate of VTE recurrence (p<0.001) and a 1.8 fold higher rate of major bleeding (p<001) compared to non-cancer patients (Table 2). CRNMB rates did not differ by cancer status.

Conclusions: In this large prospective, guideline-driven and patient-centric registry of VTE management, patients with cancer had significantly higher rate of VTE recurrence and major bleeding, compared to non-cancer patients. These data provide important estimates for power calculations for future randomized trials of VTE treatment.