Caval tumor thrombus volume influences outcomes in renal cell carcinoma with venous extension

Surgery for renal cell carcinoma with tumor thrombus has a high potential morbidity rate, and the current classification system based on proximal tumor thrombus level (TTL) has not been shown to consistently predict outcomes.

To assess the prognostic value of inferior vena cava tumor thrombus volume (IVC-TV) for determining the perioperative complications as well as with survival end points.

From June 2001 to June 2012, we identified 147 patients who underwent radical nephrectomy with venous thrombi. In total, 66 patients had IVC involvement and available imaging for review. IVC-TV was measured by cross-sectional area and height measurement for each axial slice. Linear, logistic models and Cox proportional hazard was used for analysis.

Median IVC-TV was 16.5 cm(3), and 18 patients had TTL≥III. In total, 57 Clavien I-V complications were documented in 32 patients including 3 deaths. On multivariate analysis, age>65 years, American Society of Anesthesiologists>3, and IVC-TV>15 cm(3) were independent predictors for perioperative complications. Disease progression (PoD) occurred in 78% of patients, and metastatic disease (hazard ratio [HR] = 3.33, P<0.01) and non-clear cell histology (HR = 2.98, P = 0.02) were independent predictors of PoD. Median time to death was 16 months (interquartile range: 5.2-42.9). On Cox regression analysis, metastatic disease, non-clear cell histology, IVC-TV>15 cm(3), and TTL III/IV were significantly associated with overall survival. As a preoperative variable, IVC-TV>15 cm(3) was shown to be an independent predictor of PoD (HR = 2.3, P = 0.01) and overall survival (HR = 2.21, P = 0.03).

IVC-TV has value as a prognostic indicator, which is superior to TTL in the setting of renal cell carcinoma with IVC venous thrombus.