PB1404 - Management and outcomes in patients with tumor thrombus: A retrospective cohort study

Background: Tumor thrombus can be associated with an increased risk of cancer-associated thrombosis and poorer prognosis. Additionally, the presence of concurrent bland thrombus is often a concern, but the risks and benefits of anticoagulation remain largely unknown in these patients.

Aims: To evaluate the role of anticoagulation and outcomes in patients with tumor thrombus.

Methods: We conducted a single center retrospective cohort study in patients diagnosed with tumor thrombus on imaging studies in 2019-2022. All patients were followed for 1 year from the diagnosis of tumor thrombus or until death if death occurred earlier. The primary outcome was the percentage of patients who were prescribed any dose of anticoagulation for the diagnosis of tumor thrombus (or concurrent bland thrombus). The secondary outcomes included new or progressive thrombosis, major bleeding (MB), clinically relevant non-major bleeding (CRNMB) by ISTH criteria, and mortality. We calculated the 12-month cumulative incidence of outcomes with 95% confidence interval (CI) and compared those given anticoagulation versus not, considering death as a competing risk.

Results: We included 211 patients, among whom 106 (50.2%) was given anticoagulation for tumor thrombus or concurrent bland thrombus (present in 21.8%). The most common type of cancer was hepatocellular carcinoma (28%), followed by renal cell carcinoma (27%). Splanchnic veins were the most commonly involved location (49.3%). Table 1 summarized the baseline characteristics of the cohort, stratified by anticoagulant use. Patients were more likely given anticoagulation if tumor thrombus involved inferior vena cava, heart, with concurrent VTE, or if thrombosis service is consulted. The overall 12-month incidence of venous thromboembolism was 13.0% (95%CI 8.7-18.2) and that of combined MB and CRNMB was 38.9% (95%CI 32.0-45.8), with no significant differences between groups given anticoagulation vs. not (Table 2).

Conclusion(s): Patients with tumor thrombus carry a high risk of thrombosis, bleeding, and mortality rates. Anticoagulation did not appear to improve outcomes.