Management and outcomes in patients with tumor thrombus: a retrospective cohort study

BACKGROUND: Tumor thrombus can be associated with an increased risk of venous thromboembolism (VTE) and poor prognosis. The risks and benefits of anticoagulation remain unclear. OBJECTIVES: To evaluate the role of anticoagulation and associated outcomes in patients with tumor thrombus. METHODS: We conducted a single-center retrospective cohort study in patients with tumor thrombus from 2019 to 2022. All patients were followed for 12 months from the diagnosis of tumor thrombus or until death if death occurred earlier. The primary outcome was the percentage of patients prescribed any dose of anticoagulation for tumor thrombus (or concurrent bland thrombus/VTE). The secondary outcomes included new thrombosis, major bleeding, clinically relevant nonmajor bleeding, and mortality. We calculated the 6- and 12-month cumulative incidence of outcomes with 95% CI and compared those given anticoagulation vs not, considering death as a competing risk. RESULTS: We included 211 patients, among whom 106 (50.2%; 95% CI, 47.9%-52.6%) were given anticoagulation for tumor thrombus or concurrent VTE (present in 21.8%). The most common type of cancer was hepatocellular carcinoma (28%). Splanchnic veins were the most commonly involved (49.3%). Anticoagulation was more likely used if tumor thrombus involved the inferior vena cava and/or the heart, with concurrent VTE, or if thrombosis service was consulted. The overall 12-month incidence of new VTE was 11.4% (95% CI, 7.3%-16.5%), that of major bleeding + clinically relevant nonmajor bleeding was 36.6% (95% CI, 29.6%-43.5%), and mortality of 52.5% (95% CI, 44.8%-59.6%), with no significant differences among groups given anticoagulation or not. CONCLUSION: Patients with tumor thrombus carry high risks of VTE, bleeding, and mortality. The impact of anticoagulation remains unclear.