The Role of Anticoagulation in Tumor Thrombus Associated with Renal Cell Carcinoma: A Literature Review

SIMPLE SUMMARY: Tumor thrombus occurs when tumor cells extend into a blood vessel. An estimated 10% of kidney cancer cases are complicated by tumor thrombus, often invading the renal vein with extension to the inferior vena cava. Up to 1% have tumor cells extending to the heart. The standard of care for these patients is surgical removal of the kidney tumor and the tumor thrombus. Research focuses on surgical techniques, imaging methods, and molecular markers for prognosis. The full benefit of anticoagulation remains controversial in these cases, considering unknown benefits and bleeding risk during tyrosine kinase inhibitor therapy. In this literature review, we summarize known data regarding the use of anticoagulation in the setting of kidney cancer and tumor thrombus. ABSTRACT: Tumor thrombus (TT) is a complication of renal cell carcinoma (RCC) for which favorable medical management remains undefined. While radical nephrectomy has been shown to increase overall survival in RCC patients, surgical interventions such as cardiopulmonary bypass (CPB) and deep hypothermic circulatory arrest (DHCA) utilized to perform TT resection carry high mortality rates. While it has been documented that RCC with TT is associated with venous thromboembolism (VTE) development, anticoagulation use in these patients remains controversial in clinical practice. Whether anticoagulation is associated with improved survival outcomes remains unclear. Furthermore, if anticoagulation is initiated, there is limited evidence for whether direct oral anticoagulants (DOACs), heparin, or warfarin serve as the most advantageous choice. While the combination of immunotherapy and tyrosine kinase inhibitors (TKIs) has been shown to improve the outcomes of RCC, the clinical benefits of this combination are not well studied prospectively in cases with TT. In this literature review, we explore the challenges of treating RCC-associated TT with special attention to anticoagulation. We provide a comprehensive overview of current surgical and medical approaches and summarize recent studies investigating anticoagulation in RCC patients undergoing surgery, targeted therapy, and/or immunotherapy. Our goal is to provide clinicians with updated clinical insight into anticoagulation for RCC-associated TT patients.