Analysis of clinicopathological features and prognosis in patients with papillary renal cell carcinoma

Objective To investigate the clinicopathological features and prognosis of papillary renal cell carcinoma (PRCC). Methods The clinical data of 144 PRCC cases treated in our department between Jan. 2005 and Oct. 2013 were collected and retrospectively analyzed, of whom, 97 cases were treated with radical nephrectomy and 47 with partial nephrectomy. Prognostic factors were evaluated by Log rank test. Kaplan–Meier survival curve was used to estimate the survival rate. Results The mean tumor size was 5.2 (1.0–19.0) cm; 68 cases were type 1, and 60 were type 2, the rest remained unknown; the TNM stages were as follows: 122 cases in pT1–T2, 22 cases in pT3–T4. According to the Fuhrman grading system, 112 patients were classified as grade Ⅰ–Ⅱ, 32 cases were grade Ⅲ–Ⅳ. The 3–year and 5–year survival rates were 95.6% and 92.7%, respectively. The Log rank test showed that TNM stage (P=0.002), type (P=0.019), tumor thrombus (P<0.001), regional lymph node involvement (P<0.001) and tumor necrosis (P=0.009) were associated with survival time. The multivariable Cox regression model revealed that regional lymph node involvement (P<0.05) was an independent predictor of aggressive PRCC. Conclusions PRCC is predominantly in early stage and favorable prognosis, and exhibits a low malignancy. Type 2 PRCC patients have a poor outcome when compared with type 1. Regional lymph node involvement is an independent predictor of aggressive PRCC. Fuhrman nuclear grading system is not suitable for PRCC. Key words: Papillary renal cell carcinoma; Clinical characteristics; Pathologic characteristics; Prognosis