Independent validation of the 2002 UICC TNM staging system for papillary renal cell carcinoma in a multicenter cohort

5092 Background: Papillary renal cell carcinoma (pRCC) is the second most malignant histologic subtype in nephrectomy specimens. To date, the most recognized staging system to stratify renal cancer patients is the 2002 UICC TNM classification system. Its accuracy for predicting patient outcome for pRCC is unknown. Methods: From ten urologic institutions in Germany follow-up data on 675 patients with pRCC were collected. In most cases histologic slides were available and central pathologic review was performed. The Kaplan-Meier method was used to derive the cumulative cancer-specific survival. For multivariate analysis of prognostic factors, a Cox regression analysis was performed. Results: 498 (74.1%) patients had organ-confined tumor stages (≤pT2). Synchronous distant metastases in the entire group occurred in 58 (8.7%) patients and 69 (11.2%) others developed metastatic disease during follow-up. Cancer-specific survival (CSS) was significantly related to TNM stage and histologic grading in univariate as well as in multivariate analysis (all p < 0.0001). 5-year CSS in pT1b tumors (90.0%) was significantly shorter compared to pT1a tumors (98.3%) (p = 0.017). Patients with ≥pT3 were at high risk for metastases (50.6%), while metastatic disease associated with ≤pT2 tumors occurred in 7.8% (p < 0.0001). Once metastatic disease was present, prognosis was poor (5-year CSS: 7.2%). Age was associated with a worse prognosis in the subgroup of ≥pT3 tumors in univariate (p = 0.026), but not in multivariate analysis. Conclusions: The 2002 UICC TNM staging system is applicable for pRCC. Clinical and radiologic follow-ups should be offered in frequent intervals to patients with venous thrombus and/or locally advanced disease. The role of age remains unclear, but should not be underestimated at risk stratification after tumor resection. No significant financial relationships to disclose.