The effect of TMEFF2 methylation on the tumor stage and survival outcome of clear cell renal cell carcinoma

This study aimed to investigate the methylation status of EGF-like and two follistatin-like domains 2 (TMEFF2) promoter and its correlation with tumor stage and survival outcome in renal cell carcinoma (RCC).Paraffin-embedded specimens from 42 RCC patients were analyzed for TMEFF2 methylation by methylation-specific polymerase chain reaction. The distribution of TNM/AJCC stages and survival time were compared among patients with unmethylated and methylated TMEFF2.There were 25 (59.5%) and 17 (40.5%) cases with methylated (M group) and unmethylated (M group) TMEFF2, respectively. There were more early-stage cancer patients in U group than in M group. Kaplan-Meier survival analysis showed that U group had a better but not significant survival outcome than M group (P = 0.123).These findings showed that TMEFF2 methylation is not rare in RCC, and methylation may play an important role in the tumorigenesis of ccRCC.