ABSTRACT
Objective: To investigate the clinical characteristics, treatment methods, and prognosis of metastatic papillary renal cell car-cinoma (pRCC). Methods: The clinical data of metastatic pRCC patients treated at the Department of Kidney Cancer and Melanoma, Pe-king University Cancer Hospital, were retrospectively analyzed. The prognosis of these patients was stratified through international metastatic renal cell carcinoma database consortium (IMDC) model. Survival and influencing factors were further analyzed using the Kaplan-Meier method and Cox proportional risk regression model. Results: From January 2003 to March 2018, 93 patients (median age, 50.0 years) were diagnosed with metastatic pRCC: 89 (95.7%) typeⅡcases and 4 (4.3%) typeⅠcases. The median follow-up dura-tion was 23.1 months, with 90, 44, and 14 patients having received first-line, second-line, and third-line treatments, respectively. The median overall survival (OS) of the 93 patients was (31.5±5.9) months [95% confidence interval (CI): 19.9-43.1], while the median OS of patients with low-, intermediate-, and high-risk (classified as per the International Metastatic Renal Cell Carcinoma Database Con-sortium [IMDC]) were (100.0±32.8), (38.3±8.2), and (16.4±1.2) months, respectively (high-risk vs. low/intermediate-risk, P<0.001; low-risk vs. intermediate-risk, P=0.015). The median progression free survival (PFS) with first-line treatment was (6.6±0.5) months. And the median PFS of the corresponding three groups stratified by IMDC score were (17.5±5.7), (7.1±2.3), and (5.2±1.5) months, respectively (high-risk vs . low-risk, P=0.002; high-risk vs . intermediate-risk, P=0.01). Conclusions: Metastatic pRCC is noted to have unique biologi-cal characteristics. The IMDC model can be used to predict the efficacy of first-line treatment using tyrosine kinase inhibitors as well as the prognosis of metastatic papillary renal cell carcinoma in such patients.