Molecular Markers Increase Precision of the European Association of Urology Non-Muscle-Invasive Bladder Cancer Progression Risk Groups.

Purpose: The European Association of Urology (EAU) guidelines for non-muscle-invasive bladder cancer (NMIBC) recommend risk stratification based on clinicopathologic parameters. Our aim was to investigate the added value of biomarkers to improve risk stratification of NMIBC.Experimental Design: We prospectively included 1,239 patients in follow-up for NMIBC in six European countries. Fresh-frozen tumor samples were analyzed for GATA2, TBX2, TBX3, and ZIC4 methylation and FGFR3, TERT, PIK3CA, and RAS mutation status. Cox regression analyses identified markers that were significantly associated with progression to muscle-invasive disease. The progression incidence rate (PIR = rate of progression per 100 patient-years) was calculated for subgroups.Results: In our cohort, 276 patients had a low, 273 an intermediate, and 555 a high risk of tumor progression based on the EAU NMIBC guideline. Fifty-seven patients (4.6%) progressed to muscle-invasive disease. The limited number of progressors in this large cohort compared with older studies is likely due to improved treatment in the past two decades. Overall, wild-type FGFR3 and methylation of GATA2 and TBX3 were significantly associated with progression (HR = 0.34, 2.53, and 2.64, respectively). The PIR for EAU high-risk patients was 4.25. On the basis of FGFR3 mutation status and methylation of GATA2, this cohort could be reclassified into a good class (PIR = 0.86, 26.2% of patients), a moderate class (PIR = 4.32, 49.7%), and a poor class (PIR = 7.66, 24.0%).Conclusions: We conclude that the addition of selected biomarkers to the EAU risk stratification increases its accuracy and identifies a subset of NMIBC patients with a very high risk of progression. Clin Cancer Res; 24(7); 1586-93. ©2018 AACR.

Prognostic Impact of a 12-gene Progression Score in Non-muscle-invasive Bladder Cancer: A Prospective Multicentre Validation Study.

BACKGROUND: Progression of non-muscle-invasive bladder cancer (NMIBC) to muscle-invasive bladder cancer (MIBC) is life-threatening and cannot be accurately predicted using clinical and pathological risk factors. Biomarkers for stratifying patients to treatment and surveillance are greatly needed. OBJECTIVE: To validate a previously developed 12-gene progression score to predict progression to MIBC in a large, multicentre, prospective study. DESIGN, SETTING, AND PARTICIPANTS: We enrolled 1224 patients in ten European centres between 2008 and 2012. A total of 750 patients (851 tumours) fulfilled the inclusion and sample quality criteria for testing. Patients were followed for an average of 28 mo (range 0-76). A 12-gene real-time qualitative polymerase chain reaction assay was performed for all tumours and progression scores were calculated using a predefined formula and cut-off values. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: We measured progression to MIBC using Cox regression analysis and log-rank tests for comparing survival distributions. RESULTS AND LIMITATIONS: The progression score was significantly (p<0.001) associated with age, stage, grade, carcinoma in situ, bacillus Calmette-Guérin treatment, European Organisation for Research and Treatment of Cancer risk score, and disease progression. Univariate Cox regression analysis showed that patients molecularly classified as high risk experienced more frequent disease progression (hazard ratio 5.08, 95% confidence interval 2.2-11.6; p<0.001). Multivariable Cox regression models showed that the progression score added independent prognostic information beyond clinical and histopathological risk factors (p<0.001), with an increase in concordance statistic from 0.82 to 0.86. The progression score showed high correlation (R2=0.85) between paired fresh-frozen and formalin-fixed paraffin-embedded tumour specimens, supporting translation potential in the standard clinical setting. A limitation was the relatively low progression rate (5%, 37/750 patients). CONCLUSIONS: The 12-gene progression score had independent prognostic power beyond clinical and histopathological risk factors, and may help in stratifying NMIBC patients to optimise treatment and follow-up regimens. PATIENT SUMMARY: Clinical use of a 12-gene molecular test for disease aggressiveness may help in stratifying patients with non-muscle-invasive bladder cancer to optimal treatment regimens.

Prediction of Multiple Recurrent Events: A Comparison of Extended Cox Models in Bladder Cancer.

Recurrence of bladder cancer can occur repeatedly in the same patient after treatment of the primary tumor. Models predicting the risk of a next recurrence may inform individualized decision-making on surveillance frequency. We aimed to assess the usefulness of extensions of the Cox proportional hazards model for repeated events in this context. We analyzed 531 Dutch patients with bladder cancer (1990-2012) with information on 7 prespecified predictors at the time of diagnosis of the primary and recurrent tumors. We considered 3 aspects of model variants: how to model time to the repeated events (calendar time, gap time, elapsed time); the number of preceding events (predictor, stratum variable); and the within-subject correlation (ignored in a simple Cox model, robust standard errors in a variance-correction model, random effect in a frailty model). First to fourth recurrences of bladder cancer occurred in 313, 174, 103, and 66 patients, respectively, with median calendar follow-up times of 1.1, 2.5, 3.8, and 4.5 years, respectively. We focused on gap time in the detailed analyses, allowing for clinically meaningful predictions. Variance-correction models may be useful if predictor selection is part of the model development. Frailty models may be useful when within-subject correlation is strong.

FGFR3, TERT and OTX1 as a Urinary Biomarker Combination for Surveillance of Patients with Bladder Cancer in a Large Prospective Multicenter Study.

PURPOSE: Patients with nonmuscle invasive bladder cancer are followed with frequent cystoscopies. In this study FGFR3, TERT and OTX1 were investigated as a diagnostic urinary marker combination during followup of patients with primary nonmuscle invasive bladder cancer. MATERIALS AND METHODS: In this international, multicenter, prospective study 977 patients with nonmuscle invasive bladder cancer were included. A total of 2,496 urine samples were collected prior to cystoscopy during regular visits. Sensitivity was estimated to detect concomitant recurrences. Kaplan-Meier curves were used to estimate the development of future recurrences after urinalysis and a negative cystoscopy. RESULTS: Sensitivity of the assay combination for recurrence detection was 57% in patients with primary low grade, nonmuscle invasive bladder cancer. However, sensitivity was 83% for recurrences that were pT1 or muscle invasive bladder cancer. Of the cases 2% progressed to muscle invasive bladder cancer. Sensitivity for recurrence detection in patients with primary high grade disease was 72% and 7% of them had progression to muscle invasive bladder cancer. When no concomitant tumor was found by cystoscopy, positive urine samples were more frequently followed by a recurrence over time compared to a negative urine sample (58% vs 36%, p <0.001). High stage recurrences were identified within 1 year after a positive urine test and a negative cystoscopy. CONCLUSIONS: Recurrences in patients with primary nonmuscle invasive bladder cancer can be detected by a combination of urine assays. This study supports the value of urinalysis as an alternative diagnostic tool in patients presenting with low grade tumors and as a means to identify high stage tumors earlier.

Validation of a DNA Methylation-Mutation Urine Assay to Select Patients with Hematuria for Cystoscopy.

PURPOSE: Only 3% to 28% of patients referred to the urology clinic for hematuria are diagnosed with bladder cancer. Cystoscopy leads to high diagnostic costs and a high patient burden. Therefore, to improve the selection of patients for cystoscopy and reduce costs and over testing we aimed to validate a recently developed diagnostic urine assay. MATERIALS AND METHODS: Included in study were 200 patients from a total of 3 European countries who underwent cystoscopy for hematuria, including 97 with bladder cancer and 103 with nonmalignant findings. Voided urine samples were collected prior to cystoscopy. DNA was extracted and analyzed for mutations in FGFR3, TERT and HRAS, and methylation of OTX1, ONECUT2 and TWIST1. Logistic regression was used to analyze the association between predictor variables and bladder cancer. RESULTS: Combining the methylation and mutation markers with age led to an AUC of 0.96 (95% CI 0.92-0.99) with 93% sensitivity and 86% specificity, and an optimism corrected AUC of 0.95. The AUC was higher for T1 or greater tumors compared to Ta tumors (0.99 vs 0.93). The AUC was also higher for high grade tumors compared to low grade tumors (1.00 vs 0.93). Overall negative predictive value was 99% based on the 5% to 10% prevalence of bladder cancer in patients with hematuria. This would lead to a 77% reduction in diagnostic cystoscopy. CONCLUSIONS: Analyzing hematuria patients for the risk of bladder cancer using novel molecular markers may lead to a reduction in diagnostic cystoscopy. Combining methylation analysis (OTX1, ONECUT2 and TWIST1) with mutation analysis (FGFR3, TERT and HRAS) and patient age resulted in a validated accurate prediction model.

Comprehensive Transcriptional Analysis of Early-Stage Urothelial Carcinoma.

Non-muscle-invasive bladder cancer (NMIBC) is a heterogeneous disease with widely different outcomes. We performed a comprehensive transcriptional analysis of 460 early-stage urothelial carcinomas and showed that NMIBC can be subgrouped into three major classes with basal- and luminal-like characteristics and different clinical outcomes. Large differences in biological processes such as the cell cycle, epithelial-mesenchymal transition, and differentiation were observed. Analysis of transcript variants revealed frequent mutations in genes encoding proteins involved in chromatin organization and cytoskeletal functions. Furthermore, mutations in well-known cancer driver genes (e.g., TP53 and ERBB2) were primarily found in high-risk tumors, together with APOBEC-related mutational signatures. The identification of subclasses in NMIBC may offer better prognostication and treatment selection based on subclass assignment.

Stratification based on methylation of TBX2 and TBX3 into three molecular grades predicts progression in patients with pTa-bladder cancer.

The potential risk of recurrence and progression in patients with non-muscle-invasive bladder cancer necessitates followup by cystoscopy. The risk of progression to muscle-invasive bladder cancer is estimated based on the European Organisation of Research and Treatment of Cancer score, a combination of several clinicopathological variables. However, pathological assessment is not objective and reproducibility is insufficient. The use of molecular markers could contribute to the estimation of tumor aggressiveness. We recently demonstrated that methylation of GATA2, TBX2, TBX3, and ZIC4 genes could predict progression in Ta tumors. In this study, we aimed to validate the markers in a large patient set using DNA from formalin-fixed and paraffin-embedded tissue. PALGA: the Dutch Pathology Registry was used for patient selection. We included 192 patients with pTaG1/2 bladder cancer of whom 77 experienced progression. Methylation analysis was performed and log-rank analysis was used to calculate the predictive value of each methylation marker for developing progression over time. This analysis showed better progression-free survival in patients with low methylation rates compared with the patients with high methylation rates for all markers (P<0.001) during a followup of ten-years. The combined predictive effect of the methylation markers was analyzed with the Cox-regression method. In this analysis, TBX2, TBX3, and ZIC4 were independent predictors of progression. On the basis of methylation status of TBX2 and TBX3, patients were divided into three new molecular grade groups. Survival analysis showed that only 8% of patients in the low molecular grade group progressed within 5 years. This was 29 and 63% for the intermediate- and high-molecular grade groups. In conclusion, this new molecular-grade based on the combination of TBX2 and TBX3 methylation is an excellent marker for predicting progression to muscle-invasive bladder cancer in patients with primary pTaG1/2 bladder cancer.

External validation of a multiplex urinary protein panel for the detection of bladder cancer in a multicenter cohort.

BACKGROUND: Because of the faltering sensitivity and/or specificity, urine-based assays currently have a limited role in the management of patients with bladder cancer. The aim of this study was to externally validate our previously reported protein biomarker panel from multiple sites in the United States and Europe. METHODS: This multicenter external validation study included a total of 320 subjects (bladder cancer = 183). The 10 biomarkers (IL8, MMP9, MMP10, SERPINA1, VEGFA, ANG, CA9, APOE, SDC1, and SERPINE1) were measured using commercial ELISA assays in an external laboratory. The diagnostic performance of the biomarker panel was assessed using receiver operator curves (ROC) and descriptive statistical values. RESULTS: Utilizing the combination of all 10 biomarkers, the area under the ROC for the diagnostic panel was noted to be 0.847 (95% confidence interval, 0.796-0.899), outperforming any single biomarker. The multiplex assay at optimal cutoff value achieved an overall sensitivity of 0.79, specificity of 0.79, positive prediction value of 0.73, and negative prediction value of 0.84 for bladder cancer classification. Sensitivity values of the diagnostic panel for high-grade bladder cancer, low-grade bladder cancer, muscle invasive bladder cancer, and non-muscle invasive bladder cancer were 0.81, 0.90, 0.95, and 0.77, respectively. CONCLUSIONS: Urinary levels of the biomarker panel enabled discrimination of patients with bladder cancer and controls, and the levels of biomarker subsets were associated with advancing tumor grade and stage. IMPACT: If proven to be reliable, urinary diagnostic biomarker assays can detect bladder cancer in a timely manner such that the patient can expect improvements in overall survival and quality of life.

Risk prediction scores for recurrence and progression of non-muscle invasive bladder cancer: an international validation in primary tumours.

OBJECTIVE: We aimed to determine the validity of two risk scores for patients with non-muscle invasive bladder cancer in different European settings, in patients with primary tumours. METHODS: We included 1,892 patients with primary stage Ta or T1 non-muscle invasive bladder cancer who underwent a transurethral resection in Spain (n = 973), the Netherlands (n = 639), or Denmark (n = 280). We evaluated recurrence-free survival and progression-free survival according to the European Organisation for Research and Treatment of Cancer (EORTC) and the Spanish Urological Club for Oncological Treatment (CUETO) risk scores for each patient and used the concordance index (c-index) to indicate discriminative ability. RESULTS: The 3 cohorts were comparable according to age and sex, but patients from Denmark had a larger proportion of patients with the high stage and grade at diagnosis (p<0.01). At least one recurrence occurred in 839 (44%) patients and 258 (14%) patients had a progression during a median follow-up of 74 months. Patients from Denmark had the highest 10-year recurrence and progression rates (75% and 24%, respectively), whereas patients from Spain had the lowest rates (34% and 10%, respectively). The EORTC and CUETO risk scores both predicted progression better than recurrence with c-indices ranging from 0.72 to 0.82 while for recurrence, those ranged from 0.55 to 0.61. CONCLUSION: The EORTC and CUETO risk scores can reasonably predict progression, while prediction of recurrence is more difficult. New prognostic markers are needed to better predict recurrence of tumours in primary non-muscle invasive bladder cancer patients.

HRAS mutations in bladder cancer at an early age and the possible association with the Costello Syndrome.

Bladder tumours of patients <20 years have a low incidence of genetic aberrations typically found in tumours in older patients. In this study, we investigated oncogene mutations in patients with bladder cancer (BC) <20 years and compared them to older age groups. Interestingly, we observed a relatively high number of HRAS mutations in tumour from young patients. These mutations were also highly uncommon in BCs of older patients, ie, p.(Gly12Ser) and p.(Gly12Ala). Germline mutations in the HRAS gene, especially p.(Gly12Ser/Ala), cause Costello Syndrome (CS), a severe congenital disorder. Indeed, one of the patients had been diagnosed with CS. We hypothesized that some of the other patients might be mosaic for the HRAS mutation and therefore could express some of the clinical features of CS, like tumour predisposition. Hence, we isolated DNA from microdissected stroma and analysed it for HRAS mutations. In the CS patient and in patient X, the mutation was also highly expressed in normal stroma. We conclude that patient X is possibly mosaic for the HRAS mutation. These results suggest that mosaicism for oncogenic HRAS mutations may increase the risk for developing BC at a young age.

Telomerase reverse transcriptase promoter mutations in bladder cancer: high frequency across stages, detection in urine, and lack of association with outcome.

BACKGROUND: Hotspot mutations in the promoter of the gene coding for telomerase reverse transcriptase (TERT) have been described and proposed to activate gene expression. OBJECTIVES: To investigate TERT mutation frequency, spectrum, association with expression and clinical outcome, and potential for detection of recurrences in urine in patients with urothelial bladder cancer (UBC). DESIGN, SETTING, AND PARTICIPANTS: A set of 111 UBCs of different stages was used to assess TERT promoter mutations by Sanger sequencing and TERT messenger RNA (mRNA) expression by reverse transcription-quantitative polymerase chain reaction. The two most frequent mutations were investigated, using a SNaPshot assay, in an independent set of 184 non-muscle-invasive and 173 muscle-invasive UBC (median follow-up: 53 mo and 21 mo, respectively). Voided urine from patients with suspicion of incident UBC (n=174), or under surveillance after diagnosis of non-muscle-invasive UBC (n=194), was tested using a SNaPshot assay. OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS: Association of mutation status with age, sex, tobacco, stage, grade, fibroblast growth factor receptor 3 (FGFR3) mutation, progression-free survival, disease-specific survival, and overall survival. RESULTS AND LIMITATIONS: In the two series, 78 of 111 (70%) and 283 of 357 (79%) tumors harbored TERT mutations, C228T being the most frequent substitution (83% for both series). TERT mutations were not associated with clinical or pathologic parameters, but were more frequent among FGFR3 mutant tumors (p=0.0002). There was no association between TERT mutations and mRNA expression (p=0.3). Mutations were not associated with clinical outcome. In urine, TERT mutations had 90% specificity in subjects with hematuria but no bladder tumor, and 73% in recurrence-free UBC patients. The sensitivity was 62% in incident and 42% in recurrent UBC. A limitation of the study is its retrospective nature. CONCLUSIONS: Somatic TERT promoter mutations are an early, highly prevalent genetic event in UBC and are not associated with TERT mRNA levels or disease outcomes. A SNaPshot assay in urine may help to detect UBC recurrences.

The use of molecular analyses in voided urine for the assessment of patients with hematuria.

INTRODUCTION: Patients presenting with painless hematuria form a large part of the urological patient population. In many cases, especially in younger patients, the cause of hematuria is harmless. Nonetheless, hematuria could be a symptom of malignant disease and hence most patients will be subject to cystoscopy. In this study, we aimed to develop a prediction model based on methylation markers in combination with clinical variables, in order to stratify patients with high risk for bladder cancer. MATERIAL AND METHODS: Patients (n=169) presenting with painless hematuria were included. 54 patients were diagnosed with bladder cancer. In the remaining 115 patients, the cause of hematuria was non-malignant. Urine samples were collected prior to cystoscopy. Urine DNA was analyzed for methylation of OSR1, SIM2, OTX1, MEIS1 and ONECUT2. Methylation percentages were calculated and were combined with clinical variables into a logistic regression model. RESULTS: Logistic regression analysis based on the five methylation markers, age, gender and type of hematuria resulted in an area under the curve (AUC) of 0.88 and an optimism corrected AUC of 0.84 after internal validation by bootstrapping. Using a cut-off value of 0.307 allowed stratification of patients in a low-risk and high-risk group, resulting in a sensitivity of 82% (44/54) and a specificity of 82% (94/115). Most aggressive tumors were found in patients in the high-risk group. The addition of cytology to the prediction model, improved the AUC from 0.88 to 0.89, with a sensitivity and specificity of 85% (39/46) and 87% (80/92), retrospectively. CONCLUSIONS: This newly developed prediction model could be a helpful tool in risk stratification of patients presenting with painless hematuria. Accurate risk prediction might result in less extensive examination of low risk patients and thereby, reducing patient burden and costs. Further validation in a large prospective patient cohort is necessary to prove the true clinical value of this model.

A 3-plex methylation assay combined with the FGFR3 mutation assay sensitively detects recurrent bladder cancer in voided urine.

PURPOSE: DNA methylation is associated with bladder cancer and these modifications could serve as useful biomarkers. FGFR3 mutations are present in 60% to 70% of non-muscle invasive bladder cancer (NMIBC). Low-grade bladder cancer recurs in more than 50% of patients. The aim of this study is to determine the sensitivity and specificity of a urine assay for the diagnosis of recurrences in patients with a previous primary NMIBC G1/G2 by using cystoscopy as the reference standard. EXPERIMENTAL DESIGN: We selected eight CpG islands (CGI) methylated in bladder cancer from our earlier genome-wide study. Sensitivity of the CGIs for recurrences detection was investigated on a test set of 101 preTUR urines. Specificity was determined on 70 urines from healthy males aged more than 50 years. A 3-plex assay for the best combination was developed and validated on an independent set of 95 preTUR, recurrence free, and nonmalignant urines (n=130). RESULTS: The 3-plex assay identified recurrent bladder cancer in voided urine with a sensitivity of 74% in the validation set. In combination with the FGFR3 mutation assay, a sensitivity of 79% was reached (specificity of 77%). Sensitivity of FGFR3 and cytology was 52% and 57%, respectively. CONCLUSION: The combination of methylation and FGFR3 assays efficiently detects recurrent bladder cancer without the need for stratification of patients regarding methylation/mutation status of the primary tumor. We conclude that the sensitivity of this combination is in the same range as cystoscopy and paves the way for a subsequent study that investigates a modified surveillance protocol consisting of the urine test followed by cystoscopy only when the urine test is positive.

Hypermethylation of the polycomb group target gene PCDH7 in bladder tumors from patients of all ages.

PURPOSE: Bladder tumors in patients younger than 20 years show a low incidence of the genetic and epigenetic aberrations typically found in older patients. One of the most common epigenetic aberrations in human malignancies is DNA hypermethylation. Polycomb group complexes have an important role during lineage choices in embryogenesis and their target genes are 12 times more likely to be methylated than nonpolycomb group target genes. We hypothesized that methylation of polycomb group target genes is an early event in urothelial carcinogenesis and thus might be observed in young patients. MATERIALS AND METHODS: We stratified 167 patients by age into 4 groups, including age less than 20 years in 14, 20 to 40 in 48, 40 to 60 in 47 and greater than 60 in 58. Five previously identified polycomb group target genes (MEIS1, ONECUT2, OTX1, PCDH7 and SOX21) were selected for methylation analysis. Methylation ratios were calculated by using the unmethylated and methylated signal. The outcome represented the fraction of methylated cells within one tumor. Genes with similar methylation ratios in all age groups were considered as potential bladder cancer initiating candidates. RESULTS: Three genes showed higher methylation ratios in tumors from older patients, including ONECUT2, SOX21 and OTX1 (each p <0.001). MEIS1 showed a similar methylation ratio in all groups but the median methylation ratio was low. PCDH7 showed a similar median methylation percent in all age categories, ie 54% at less than 20, 59% at 20 to 40, 59% at 40 to 60 and 67% at greater than 60 years (p = 0.1). CONCLUSIONS: Tumors from young patients showed less methylation for most markers. PCDH7 showed high methylation ratios in all age categories. Therefore, it could have an important role in early urothelial carcinogenesis.

Combinations of urinary biomarkers for surveillance of patients with incident nonmuscle invasive bladder cancer: the European FP7 UROMOL project.

PURPOSE: We determined a combination of markers with optimal sensitivity to detect recurrence in voided urine after resection of an incident low grade, nonmuscle invasive bladder tumor. MATERIALS AND METHODS: A total of 136 patients with G1/G2 nonmuscle invasive bladder tumor were included in the study at transurethral resection of the incident tumor. At least 3 followup urine samples were required for patient selection. DNA was extracted from the incident tumor and cell pellets of subsequently collected urine samples. We performed FGFR3, PIK3CA and RAS mutation analysis, and microsatellite and methylation analysis on tissue and urine DNA samples. RESULTS: We obtained 716 urine samples. The 136 patients experienced a total of 552 recurrences during a median 3-year followup. Sensitivity for detecting a recurrent tumor varied between 66% and 68% for the molecular tests after patient stratification based on tumor DNA analysis. A combination of markers increased sensitivity but decreased the number of patients eligible for a certain test combination. Combining urine cytology with FGFR3 analysis without stratifying for FGFR3 status of the incident tumor increased sensitivity from 56% to 76%. CONCLUSIONS: A combination of markers increased the percentage of patients eligible for urine based followup and the sensitivity of recurrence detection. Adding FGFR3 analysis to urine cytology could be valuable for noninvasive followup of patients with nonmuscle invasive bladder cancer.

Down-staging (

Urothelial cell carcinoma (UCC) with musculus detrusor (MD) invasion is treated by cystectomy. Subsequent pathologic evaluation of cystectomies does not reveal MD invasion (

A methylation assay for the detection of non-muscle-invasive bladder cancer (NMIBC) recurrences in voided urine.

OBJECTIVE: To develop a methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) assay for the detection of non-muscle invasive bladder cancer (NMIBC) recurrences in voided urine. PATIENTS AND METHODS: Genes frequently methylated in NMIBC tumours (n= 37) were selected to develop a BC-specific MS-MLPA assay. Genes methylated in blood from patients with BC (n= 29) and genes methylated in urine from patients with no history of BC (n= 46) were excluded. A four-gene panel with the highest predictive value was selected from the initial assay. This four-gene panel was tested and validated on urine from patients with a histologically confirmed recurrence (n= 68 test set; n= 49 validation set) and urine samples from patients without BC (n= 91, test set) and urine from recurrence-free BC (rec-free BC) patients (n= 60, validation set). A model was developed to predict the probability of having a recurrence based on methylation of the four-gene panel and a threshold probability with the highest sensitivity and specificity was determined. The outcome of the model was validated on BC urine samples (n= 65) and on urine samples from rec-free BC patients (n= 29). RESULTS: The BC MS-MLPA assay consisted of 23 methylation probes. The selected four-gene panel included: APC_a, TERT_a, TERT_b, and EDNRB. This panel reached an area under the receiver operating characteristic curve (AUC) of 0.82 (test set) and AUC 0.69 (validation set). Sensitivity and specificity for the detection of a concomitant tumour were 63.3% and 58.3% respectively (test set) and 72.3% and 55.2%, respectively (validation set). CONCLUSIONS: We have developed a methylation detection assay specifically for the detection of recurrences in patients with NMIBC in voided urine. The findings are promising and improvement of this test could eventually contribute to a more individualized patient friendly surveillance.