ABSTRACT
Cervical intraepithelial neoplasia (CIN) grade 2/3 has a high spontaneous regression rate, especially among women ≤29 years of age. To reduce overtreatment, reliable prognostic biomarkers would be helpful. The main aim of this study was to analyze the negative predictive value of the methylation marker panel GynTect® for lesion regression. In this prospective, multicenter, longitudinal observational proof-of-concept study, women aged ≤29 years with histologically confirmed CIN2 (n = 24) or CIN3 (n = 36) were closely monitored without treatment for up to 24 or 12 months, respectively. The outcome was either regression, persistence, or progression of the lesion. For each patient, a single baseline sample (V0) for cytology, hrHPV detection and methylation analysis was taken. In a primary analysis, the negative predictive value (NPV) of a GynTect®-negative test result at V0 for regression was determined. We tested the null hypothesis NPV ≤ 70% against the alternative hypothesis NPV ≥ 90%. Twelve of the eighteen GynTect®-negative CIN2 patients showed regression (NPV = 67%, 90% CI 44-85%, p = 0.53). Of the 27 GynTect®-negative CIN3 lesions, 15 regressed (NPV = 56%, 90% CI 38-72%, p = 0.92). Although the majority of GynTect®-negative lesions regressed, the postulated NPV of ≥90% was not observed. Thus, the clinical relevance for an implementation of the GynTect® assay for patients undergoing watchful waiting remains questionable. Further studies with longer observation periods should be undertaken.
ABSTRACT
INTRODUCTION: Cystoscopy and transurethral resection are the current reference standard tests to diagnose and histologically confirm non-muscle-invasive bladder cancer (NMIBC). In other tumor entities (ie, colon carcinoma, cervical cancer), DNA methylation markers have been approved as diagnostic tests with high diagnostic power. In our case-control study, we used an approved molecular cervical cancer diagnostics test that includes 6 DNA methylation markers (GynTect) for the detection of bladder cancer. PATIENTS AND METHODS: We included samples from 40 patients with bladder cancer and 34 control subjects. In a pilot study, we analyzed DNA methylation in 38 tumor tissues and 4 healthy ureters using methylation-specific polymerase chain reaction. Subsequently, we determined the sensitivity and specificity of the GynTect for the detection of bladder cancer in urine sediments from 40 patients with bladder cancer and 30 control subjects with benign prostatic hyperplasia or urolithiasis. RESULTS: The markers showed very different methylation rates in the NMIBC tissues, ranging from 2.6% to 78.9%. No methylation of any of the markers was detectable in the healthy ureters. Using the urine sediments from the patients with cancer and control subjects, we found surprisingly high sensitivity and specificity for the GynTect assay (60% and 96.7%, respectively). The application of different algorithms for evaluation of the markers included in GynTect resulted in a sensitivity of ≤ 90% and specificity of ≤ 100%. CONCLUSION: The GynTect assay, originally designed for cervical cancer diagnostics, showed unexpectedly high diagnostic accuracy for bladder cancer detection. The inclusion of additional methylation markers might allow for the development of a suitable diagnostic marker set based on the GynTect test for NMIBC diagnostics.