Clinical potential of TCF21 methylation in the diagnosis of renal cell carcinoma

The aim of the present study was to investigate the clinical potential of transcription factor (TCF) 21 methylation in the diagnosis of renal cell carcinoma (RCC). TCF21 methylation levels were quantified in renal tissues (55 cases of RCC tissue and 22 cases of normal tissue) and urine samples (33 cases of urine samples with RCC and 15 cases of normal urine samples) using pyrosequencing. Spearman's rank correlation coefficient was used to investigate the correlation between TCF21 methylation levels and clinical parameters (gender, age, smoking history, Fuhrman grade and clinical stage). The receiver operating characteristic (ROC) curve was utilized to evaluate the accuracy of predictive diagnosis of RCC. TCF21 methylation levels were significantly increased in RCC samples compared with normal renal tissues and urine samples. The Spearman's correlation analysis revealed that the TCF21 methylation level was positively associated with age (P=0.002), smoking (P=0.017) and Fuhrman grade (P=0.045) in RCC tissues and was positively associated with tumor size (P<0.001), Fuhrman grade (P=0.017) and clinical stage (P=0.017) in urine samples. ROC curves revealed that the cut-off value, sensitivity and specificity were 23.61, 89.00 and 61.90%, respectively in tissue samples, and 26.84, 79 and 100%, respectively in urine samples. Furthermore, there were significant differences in the area under the curve between the tissue and urine samples (P=0.004). The results of the present study indicate that TCF21 may be used as a biomarker for diagnosing RCC, and TCF21 methylation levels in urine samples may be a useful means of diagnosing RCC.