Accurate detection of upper tract urothelial carcinoma in tissue and urine by means of quantitative GDF15, TMEFF2 and VIM promoter methylation.

AIM OF THE STUDY

Upper tract urothelial carcinoma (UTUC) accounts for 5-10% of all urothelial tumours. It is mostly diagnosed at advanced stages, entailing a worse prognosis, owing to the lack of early and specific symptoms as well as of effective diagnostic tools. We previously identified a panel of epigenetic biomarkers (GDF15, TMEFF2 and VIM promoter methylation) that accurately identifies bladder cancer in urine. Herein, we assessed the performance of the same panel for UTUC detection and prognosis, in tissue and urine.

MATERIAL AND METHODS

Methylation levels of reference and target genes were determined using real-time quantitative methylation-specific polymerase chain reaction (MSP) in bisulphite-modified DNA of 57 UTUC tissues, 36 normal upper tract urothelium (NUTUs), 22 urines from UTUC suspects and 20 urines from controls. Receiver operator characteristics (ROC)-curve analysis was performed to determine the performance of the biomarker panel and survival analyses were conducted to evaluate their prognostic value.

RESULTS

Methylation levels of GDF15, TMEFF2 and VIM were significantly higher in UTUC compared to NUTUs (P=0.022; P<0.001; P<0.001, respectively). The panel accurately identified UTUC with 100% and 91% sensitivity, corresponding to an area under the curve of 1.000 and 0.923 in tissue and urines, respectively, with 100% specificity. Low VIM promoter methylation levels independently predicted poor disease-specific survival.

CONCLUSIONS

GDF15, TMEFF2 and VIM promoter methylation allows for accurate identification of UTUC, in tissue and urine and VIM methylation provides relevant prognostic information, especially in high-stage disease. This assay may improve the clinical management of UTUC patients.