Renal Cell Carcinoma with Venous Tumor Thrombus: 15 Years of Experience in an Oncology Center

<b>Background:</b> The purpose of this study is to report the experience of a single Portuguese oncology center in the management of patients with renal cell carcinoma (RCC) and venous tumor thrombus (VTT). <b>Methods:</b> This is a retrospective analysis of all patients with RCC and VTT surgically treated in our center between 2008 and 2023. Only patients with VTT up to level III (Mayo Clinic classification) were included. Patient, tumor characteristics and peri-operative outcome data were registered. Administration of systemic therapy was performed upon progression. Survival analysis was conducted with the collected data. <b>Results:</b> A total of 64 patients (n = 16 women) were included in this study. The mean age at diagnosis was 66.3 ± 10.7 years old. The VTT level was 0, I, II and III in 40 (62.5%), 12 (18.7%), 6 (9.4%) and 6 (9.4%) patients, respectively. Nine patients (14.1%) had distant metastasis at diagnosis. No peri-operative deaths occurred, and the major complication rate was 3.1%. Histology revealed 98.4% of clear cell RCC, with sarcomatoid differentiation present in 12.5% of the cases. A negative margin status was achieved in 54 (84.4%) patients. Systemic therapy was administered in 24 (37.5%) patients during follow-up. The median progression-free (PFS), cancer-specific (CSS) and overall (OS) survival were 23, 60 and 48 months, respectively. In multivariable analysis, significant predictors of CSS were tumor size, sarcomatoid differentiation and collecting system invasion. <b>Conclusions:</b> Radical nephrectomy with VTT excision up to level III is a feasible and safe procedure. Patients with large tumor size, sarcomatoid differentiation and collecting system invasion are at the highest risk and should be closely monitored.