Prognostic Factors for Renal Cell Carcinoma With Tumor Thrombus Extension

PURPOSE: We identified prognostic factors for renal cell carcinoma with tumor thrombus extension and assessed whether the current T3 classification could be improved. MATERIALS AND METHODS: We studied clinicopathological parameters in 321 consecutive patients who were surgically treated for renal cell carcinoma with tumor thrombus extension. Disease specific survival was evaluated with univariate and multivariate analysis. Harrell's C-index was used to assess the prognostic accuracy of prognostic models. RESULTS: Tumor thrombus extended into the renal vein in 166 patients, the inferior vena cava in 137 and the atrium in 18. Metastatic renal cell carcinoma was found in 198 patients (62%). The thrombus level had no impact on clinicopathological parameters or survival but perioperative morbidity and mortality increased with cranial extension of the thrombus. Mean followup was 49 months. Five and 10-year disease specific survival rates were 36% and 24%, respectively. On multivariate analysis Eastern Cooperative Oncology Group performance status, lymph node and distant metastases, sarcomatoid features and perinephric fat invasion were independent prognostic factors. Weight loss, anemia, collecting system invasion, incomplete surgical resection, nuclear grade and T classification were also significant prognosticators on univariate analysis. For patients with advanced disease the number of metastatic sites and the disease-free interval further predicted prognosis. The overall immunotherapy response rate was 19%, which decreased with cranial extension of the thrombus. Redefinition of the T3 classification with the incorporation of fat invasion improved prognostic accuracy, as shown by an increase in the C-index. CONCLUSIONS: Eastern Cooperative Oncology Group performance status, metastatic status, sarcomatoid features and concomitant perinephric fat invasion are the most powerful prognostic factors of survival in renal cell carcinoma with tumor thrombus extension. Our data indicate that a redefinition of the current T3 classification may improve its predictive accuracy. We propose that T3 renal cell carcinoma with fat invasion or thrombus extension alone should be classified as T3a, while that with thrombus extension plus fat invasion should be classified as T3b.