Clinical and Pathologic Features Associated with Prognosis in Patients with Papillary Renal Cell Carcinoma
William R Sukov, Christine M Lohse, Bradley C Leibovich, Houston Thompson, John C Cheville. Mayo Clinic College of Medicine, Rochester, MN
Background: The most common classification system for papillary renal cell carcinoma (PRCC) divides these tumors into two distinct subtypes -type 1 or basophilic and type 2 or eosinophilic - based on specific histologic features. Features predictive of outcome in patients with PRCC vary by study; several studies indicate that type 2 PRCC are associated with a significantly worse prognosis than type 1. However, this is not a consistent finding, and there are issues related to PRCC tumor heterogeneity that make the identification of prognostic features difficult. Identification of prognostic features is further complicated by the lower frequency of PRCC. The purpose of the current study is to investigate a large series of patients with PRCC to determine the prognostic value of various clinical and pathologic features.
Design: Upon approval from the Institutional Review Board, we identified 395 consecutive patients from the Mayo Clinic Nephrectomy Registry treated with radical nephrectomy or nephron-sparing surgery for unilateral, sporadic, PRCC between 1970 and 2002. The clinical and pathologic features for each case were reviewed. The associations of clinical and pathologic features with death from PRCC were evaluated using Cox proportional hazards regression models and summarized with hazard ratios and 95% confidence intervals. Cancer-specific survival was estimated using the Kaplan-Meier method.
Results: At last follow-up, 45 patients died from PRCC at a median of 2.8 years following surgery. By univariate analyses symptoms, tumor thrombus, tumor size, perinephric/renal sinus fat invasion, regional lymph node involvement, distant metastasis, the 2010 TNM stage groupings, grade, tumor necrosis, sarcomatoid differentiation, and PRCC type were associated with death from RCC. Grade was more strongly associated with death from PRCC (hazard ratio 3.97; 95% CI 2.14-7.39; p<0.001) than PRCC type(hazard ratio 2.16; 95% CI 1.20-3.89; p=0.010). Multivariable analyses indicated that symptoms, tumor size, the 2010 TNM stage groupings, grade, and sarcomatoid differentiation were jointly significantly associated with death from RCC.
Conclusions: This large series of patients with PRCC identifies features associated with death from RCC, and confirms that grade is more predictive of outcome than PRCC type.
Category: Genitourinary (including renal tumors)
Tuesday, March 20, 2012 2:15 PM
Platform Session: Section A, Tuesday Afternoon