DNA methylation analysis in urinary samples: A useful method to predict the risk of neoplastic recurrence in patients with urothelial carcinoma of the bladder in the high-risk group

Background: Recently, it was reported that the Bladder EpiCheck test is likely to represent a valid tool in the diagnostic process of patients who have suspected bladder carcinoma, with some controversial management decisions because of the technical limitations of cytology. Methods: Two hundred ninety patients with a diagnosis of nonmuscle-invasive bladder carcinoma who were admitted at the authors' department from March 2019 to December 2019 were treated and followed for 1 year. During follow-up, all patients were evaluated by voided urine cytology, white-light cystoscopy (according to European Association of Urology guidelines), and the Bladder EpiCheck test. Results: The cytologic diagnoses of high-grade urothelial carcinoma (HGUC) and suspicious for HGUC were histologically confirmed in 5 of 20 patients (25%) who had quantitative Bladder EpiCheck scores (EpiScores) from 60 to 69, in 23 of 36 patients (64%) who had EpiScores from 70 to 79, and in 42 of 56 patients (75%) and 57 of 63 patients (90%) who had EpiScores between 80 and 89 and EpiScores >90, respectively. Of 48 patients who had a cytologic diagnosis of HGUC or suspicious for HGUC with EpiScores ≥60 and negative histology, 20 (42%) had a recurrence of HGUC, which was cytologically and histologically confirmed, at 6-12 months during follow-up. Conclusions: To the best of the authors' knowledge, this is the first study in which patients at high risk for HGUC were stratified using the Bladder EpiCheck EpiScore. The results validate this methylation analysis tool as a useful method for predicting recurrent HGUC during the follow-up of patients with nonmuscle-invasive bladder carcinoma.