To investigate the clinicopathological features and prognostic factors of papillary renal cell carcinoma (pRCC).

The clinicopathological features of 117 pRCC patients admitted from January 2012 to October 2019 were retrospectively analyzed, including 40 cases from Peking University Cancer Hospital, 24 cases from Beijing Hospital, and 53 cases from Xiangya Hospital of Central South University. There were 88 male and 29 female patients included in this study, with a mean age of 53 (ranging from 21-82). Fifty-seven tumors were located in the left kidney and 60 in the right kidney. Fifty cases underwent partial nephrectomy and 67 cases underwent radical nephrectomy. Kaplan-Meier curve and log-rank test were used to describe the progression-free survival (PFS). Cox regression model was used for univariate and multivariate analysis to identify the prognostic factors.

Of the 117 patients, the largest tumor diameter was 0.8 to 15.0 cm, with an average of 5.6 cm. There were 29 patients with type 1 pRCC and 88 patients with type 2. Postoperative pathological staging showed 74 cases (63.2%) of pT₁ stage, 19 cases (16.2%) of pT₂ stage, 14 cases (12.0%) of pT₃ stage, and 10 cases (8.5%) of pT₄ stage. WHO/ISUP pathological classification showed 11 cases (9.4%) of grade Ⅰ, 49 cases (41.9%) of grade Ⅱ, 45 cases (38.5%) of grade Ⅲ, and 12 cases (10.3%) of grade Ⅳ. Nineteen cases (16.2%) were positive for vascular cancer embolus. There were 32 cases (27.4%) with positive tumor necrosis. The overall follow-up was 24 months. Survival analysis showed that the 3-year PFS rate was 79.9%. The median follow-up time for 29 patients with type 1 pRCC was 43 months, and the 3-year PFS rate was 96.6%. The median follow-up for 88 patients with type 2 pRCC was 17 months, and the 3-year PFS rate was 72.1 %. The prognosis of patients with type 1 pRCC was significantly better than that of type 2(P=0.025). Univariate analysis showed that tumor size, surgical procedure, pT staging, vascular cancer embolus and tumor necrosis were closely related to the prognosis of patients with type 2 pRCC. Stratified analysis of the prognosis of type 2 pT₁ stage patients showed no statistically significant difference in progression-free survival between partial nephrectomy and radical nephrectomy group(P=0.230).

The incidence of pRCC in China is lower than that reported in foreign countries, and type 2 is more common than type 1.Compared with type 1 pRCC, type 2 pRCC had a later pT stage and a higher pathological grade. For type 2 pRCC at stage pT₁, partial nephrectomy is not inferior to radical nephrectomy, and nephron sparing surgery may be considered.

Carcinoma, renal cell; Papillary renal cell carcinoma; Clinical features; Pathological features; Prognosis