Prognostic significance of venous thrombus in renal cell carcinoma. Are renal vein and inferior vena cava involvement different?

PURPOSE: The prognostic significance of the level of venous involvement in renal cell carcinoma (RCC) is controversial. It has been suggested that the 1997 TNM classification of venous involvement system should be revised.

MATERIALS AND METHODS: The records of 226 patients who underwent a nephrectomy and tumor thrombectomy, 117 for renal vein (RV) and 109 for inferior vena cava (IVC) involvement, between 1989 and 2001 were reviewed and compared to those of 654 patients undergoing nephrectomy without venous involvement.

RESULTS: In patients with localized RCC (N0M0), the risk of recurrence after nephrectomy was significantly increased in patients with venous thrombus compared to patients without venous thrombus (p = 0.005). However, the difference was not significant in a multivariate analysis including T stage (1, 2, 3 or 4), Fuhrman grade and Eastern Cooperative Oncology Group performance status. In patients with localized RCC disease specific survival was similar (p = 0.536) in patients with RV (T3b) and IVC involvement below the diaphragm (T3b). However, patients with IVC involvement above the diaphragm (T3c) had a significantly worse survival rate even after controlling for Fuhrman grade and Eastern Cooperative Oncology Group performance status in a multivariate analysis (p = 0.020). All patients treated for metastatic RCC had a similar prognosis regardless of the level of venous involvement.

CONCLUSIONS: For patients with pT3b disease, local tumor stage and grade are better predictors of prognosis than extent of venous involvement. Based on our data we support the current TNM classification of venous involvement with RV and IVC invasion categorized as T3b and IVC involvement above the diaphragm categorized as T3c.