Primary Primitive Neuroectodermal Tumor Of The Kidney:Pooled Analysis Of142Published Cases And Review Of Literature

Background and Objectives:Primitive neuroectodermal tumor (PNET) arising in the kidney is extremely rare, aggressive and highly malignant. There is still no standard treatment of the neoplasm. The purpose of our study was to describe the clinical features and evaluate the important factors affecting the prognosis of patients with renal PNET.Methods:The authors retrospectively reviewed142PNET patients reported in the literature with primary renal localization. The patients’information and survival data were extracted from abstracts or full text. All data were analyzed by SPSS16.0. Statistical analyses were performed using Kaplan-Meier survival curves, log-rank test and COX proportional hazard regression model multivariate analysis. P-value less than0.05was considered to be statistically significant.Results:Of142cases, including83men and59women, the sex ratio (male:female) of PNET is1.41:1. The median age of the142patients was28old years (mean30.18, range3to78). The predominant symptoms were pain (n=95), hematuria (n=60), and mass (n=56), weight loss (n=16) and fever (n=8).59patients located in the left kidney,77cases right. The median follow-up time was12months (mean17months, range0.5 to90). Palpable tumor masses (log-rank, P=0.017) were identified as unfavorable prognostic markers. Patients with lymph node metastasis had a significantly worse outcome (log-rank, P=0.001). Distant metastasis is a poor sign (log-rank, P=0.000). COX regression analysis demonstrated that palpable masses and distant metastases were the key factors affecting the prognosis of the renal PNET. One-year over survival rate was73.8%, three-year over survival rate was43.6%, and five-year over survival rate was37.4%.Conclusions:Renal PNET occurs most frequently in older children and young adults, a little men predominance. Clinical symptoms, laboratory results and medical imaging were similar to other tumors. The diagnosis of PNET is based on the pathologic findings. Furthermore, this study indicated palpable masses and distant metastasis are associated with a shorter cancer-specific survival. Despite all treatment options, the prognosis of the renal PNET is extremly poor.