Clinicopathological Features and Prognostic Outcomes of Papillary Renal Cell Carcinoma

Purpose: Although papillary renal cell carcinoma (pRCC) is the second common renal malignant tumor, the current understanding of pRCC is poor. This study aims to explore the clinicopathological features and prognostic factors of pRCC. Methods: From August 2007 and August 2017, 87 patients diagnosed with pRCC by postoperative pathology were enrolled. The clinicopathological features between type1 pRCC and type2 pRCC were compared by Chi-square test, Fisher's exact test, or t-test. The Kaplan-Meier method was performed to estimate progression-free survival (PFS). Univariate and multivariate cox regression models were used to verify the prognostic factors. Results: Of the 87 cases, the median tumor diameter was 5.3cm. Twenty-nine patients were diagnosed with type1 pRCC and 58 patients with type2 pRCC. According pathological stage, 59 (67.8%) cases were in pT1 stage, 19 (21.8%) in pT2 stage, and 9 (10.4%) in pT3 stage. WHO/ISUP pathological grade revealed that 56 (64.4%) patients were in grade I, 17 (19.5%) in grade II, 7 (8.05%) in grade III, and 7 (8.05%) in grade IV. The median follow-up time was 57.0months, and the 1-, 3-year PFS was 95.4%, and 80.8%, respectively. For type1 and type2 pRCC, 3-years PFS was 93.0% and 74.9%, respectively. Survival of type1 pRCC was better than that of type2 (P=0.027). Patients with late pT stage, lymph node metastasis, distant metastasis, high pathological grade, and large size exhibited worse survival. pTNM stage, pathological grade, and tumor types were potentially related to prognosis for PFS. However, an independent prognostic factor affecting PFS was not found in multivariate regression models. For patients with the pT1 stage, nephron-sparing surgery (NSS) and radical nephrectomy (RN) did not affect the PFS, ignoring tumor types (P=0.45). Conclusion: Type2 pRCC is more than type1 pRCC and has an advanced TNM stage and a higher pathological grade. For patients with pRCC with the pT1 stage, the outcome of NSS is not inferior to that of RN.