Abstract:
Objective To construct a prognostic nomogram based on epithelial-stromal interaction protein 1 (EPSTI1) and predict the prognosis of clear cell renal cell carcinoma (ccRCC).
Methods A retrospective analysis was performed from January 2012 to December 2015 at The First Affiliated Hospital of Fujian Medical University, on 221 patients with ccRCC who underwent surgical treatment in our center and 533 patients with ccRCC in The Cancer Genome Atlas (TCGA) database. Immunohistochemical (IHC) staining was performed on adjacent normal and cancerous tissues to analyze the expression level of EPSTI1 and its correlation with clinicopathological characteristics. Kaplan-Meier survival analysis was performed for the overall survival (OS) and disease-free survival (DFS) of patients with high and low EPSTI1 expression levels. Univariate and multivariate Cox proportional hazards models were used to analyze the prognostic factors for OS, and a nomogram model was constructed and verified.
Results The IHC scores and mRNA expression levels of EPSTI1 were significantly higher in ccRCC tissues than in normal tissues (all P<0.001). EPSTI1 was expressed at higher levels in cancer tissues at higher T stages (P=0.036, P=0.006). The EPSTI1 protein expression level was related to the maximum tumor diameter and TNM stage (P=0.002, P=0.032, respectively). The OS and DFS were higher in the low-EPSTI1-expression group than the high-EPSTI1-expression group (P=0.046, P=0.003, P=0.001). Univariate and multivariate Cox regression analyses showed that a high EPSTI1 protein expression level, WHO/ISUP grade, and AJCC/TNM stage were independent risk factors for poor prognosis (P=0.009, P=0.039, P<0.001). The prognostic nomogram model constructed based on the above variables was superior to the AJCC/TNM stage in predicting the 5-year OS, and the calibration curve showed that the predicted value of the model was consistent with the actual value.
Conclusions The nomographic model based on EPSTI1, AJCC/TNM staging and WHO/ISUP staging has a strong predictive ability for the prognosis of renal clear cell carcinoma.