Inferior vena cava (IVC) thrombus is a rare but serious complication in renal cell carcinoma (RCC) and other malignancies. Managing tumor-related IVC thrombus is challenging due to complex surgical demands and high mortality. Understanding the prognostic factors influencing overall survival (OS) and disease-free survival (DFS) is crucial for improving surgical strategies and patient outcomes.

A retrospective analysis was conducted on 63 patients with IVC thrombus from RCC or other malignancies at a single center between 2013 and 2024. Cox regression analysis identified independent prognostic factors for OS and DFS, while Kaplan-Meier and Receiver operating characteristic (ROC) analyses assessed survival and predictive factors.

Among the 63 patients, 33 (52.4%) had clear cell renal cell carcinoma (ccRCC), 16 (25.4%) had non-ccRCC, and 14 (22.2%) had non-RCC malignancies. In the comparison between ccRCC and non-ccRCC, multivariate Cox regression identified M1 status (HR = 5.61, p = 0.004) as an independent predictor of poor survival. Thrombus Level IV (HR = 3.62, p = 0.041), increased blood loss (≥1000 mL, HR = 2.51, p = 0.035), prolonged operation time (≥415 min, HR = 5.12, p = 0.003), and delayed feeding (≥2.5 days, HR = 2.95, p = 0.009) were significant in univariate analysis but not in multivariate analysis. The 5-year OS and DFS rates were 40.04% and 25.61%, respectively, across all patients, including non-RCC cases. Kaplan-Meier analysis indicated improved survival with shorter operation time and earlier feeding (both p < 0.01). ROC analysis identified operation time (AUC = 0.647, p = 0.046) and feeding time (AUC = 0.679, p = 0.015) as significant predictors.

M1 status was an independent predictor of poor survival. Although thrombus Level IV, increased blood loss, prolonged operation time, and delayed feeding were linked to poorer survival in univariate analysis, they were not significant in multivariate analysis. Kaplan-Meier analysis indicated improved survival with shorter operation time and earlier feeding. Strategies to reduce blood loss, shorten surgical time, and facilitate early feeding may improve outcomes. Further studies may focus on refining these strategies and validating their impact on survival in patients with IVC thrombus.