Equipping computational pathology systems with artifact processing pipelines: a showcase for computation and performance trade-offs.

BACKGROUND: Histopathology is a gold standard for cancer diagnosis. It involves extracting tissue specimens from suspicious areas to prepare a glass slide for a microscopic examination. However, histological tissue processing procedures result in the introduction of artifacts, which are ultimately transferred to the digitized version of glass slides, known as whole slide images (WSIs). Artifacts are diagnostically irrelevant areas and may result in wrong predictions from deep learning (DL) algorithms. Therefore, detecting and excluding artifacts in the computational pathology (CPATH) system is essential for reliable automated diagnosis. METHODS: In this paper, we propose a mixture of experts (MoE) scheme for detecting five notable artifacts, including damaged tissue, blur, folded tissue, air bubbles, and histologically irrelevant blood from WSIs. First, we train independent binary DL models as experts to capture particular artifact morphology. Then, we ensemble their predictions using a fusion mechanism. We apply probabilistic thresholding over the final probability distribution to improve the sensitivity of the MoE. We developed four DL pipelines to evaluate computational and performance trade-offs. These include two MoEs and two multiclass models of state-of-the-art deep convolutional neural networks (DCNNs) and vision transformers (ViTs). These DL pipelines are quantitatively and qualitatively evaluated on external and out-of-distribution (OoD) data to assess generalizability and robustness for artifact detection application. RESULTS: We extensively evaluated the proposed MoE and multiclass models. DCNNs-based MoE and ViTs-based MoE schemes outperformed simpler multiclass models and were tested on datasets from different hospitals and cancer types, where MoE using (MobileNet) DCNNs yielded the best results. The proposed MoE yields 86.15 % F1 and 97.93% sensitivity scores on unseen data, retaining less computational cost for inference than MoE using ViTs. This best performance of MoEs comes with relatively higher computational trade-offs than multiclass models. Furthermore, we apply post-processing to create an artifact segmentation mask, a potential artifact-free RoI map, a quality report, and an artifact-refined WSI for further computational analysis. During the qualitative evaluation, field experts assessed the predictive performance of MoEs over OoD WSIs. They rated artifact detection and artifact-free area preservation, where the highest agreement translated to a Cohen Kappa of 0.82, indicating substantial agreement for the overall diagnostic usability of the DCNN-based MoE scheme. CONCLUSIONS: The proposed artifact detection pipeline will not only ensure reliable CPATH predictions but may also provide quality control. In this work, the best-performing pipeline for artifact detection is MoE with DCNNs. Our detailed experiments show that there is always a trade-off between performance and computational complexity, and no straightforward DL solution equally suits all types of data and applications. The code and HistoArtifacts dataset can be found online at Github and Zenodo , respectively.

RNA-based urinary assays for non-muscle invasive bladder cancer.

PURPOSE OF REVIEW: To provide an overview of the recent literature on RNA-based molecular urine assays for the diagnosis and surveillance of non-muscle invasive bladder cancer (NMIBC). RECENT FINDINGS: Articles were eligible for inclusion if performance metrics sensitivity, specificity, and negative-predictive value (NPV) were reported or could be calculated. Only prospective studies published between 2020-2022 were included. Five out of fourteen studies addressed the primary diagnostic setting; the proportion of gross hematuria patients in all study populations was >50%. Only one study reported performance metrics within a microscopic hematuria subgroup. This study evaluated Xpert Bladder and reported a sensitivity: 73%, specificity: 84%, NPV: 99%, and PPV: 12%. Ten studies assessed test performance during surveillance for NMIBC. For the detection of high-grade (HG) and high-risk (HR) NMIBC, sensitivity, specificity, NPV, and PPV varied between 78-100%, 64-89%, 97.0-99.7%, and 9.2-39%. SUMMARY: Multiple RNA-based urine assays have been investigated for the detection of urothelial cancer in the primary or surveillance setting. However, studies included within this review have important limitations, hampering the interpretation of study results. As such, performance metrics should be interpreted with caution and further research is required to evaluate the clinical impact of RNA-based urine assays in daily practice.

The clonal relation of primary upper urinary tract urothelial carcinoma and paired urothelial carcinoma of the bladder.

The risk of developing urothelial carcinoma of the bladder (UCB) in patients treated by radical nephroureterectomy (RNU) for an upper urinary tract urothelial carcinoma (UTUC) is 22% to 47% in the 2 years after surgery. Subject of debate remains whether UTUC and the subsequent UCB are clonally related or represent separate origins. To investigate the clonal relationship between both entities, we performed targeted DNA sequencing of a panel of 41 genes on matched normal and tumor tissue of 15 primary UTUC patients treated by RNU who later developed 19 UCBs. Based on the detected tumor-specific DNA aberrations, the paired UTUC and UCB(s) of 11 patients (73.3%) showed a clonal relation, whereas in four patients the molecular results did not indicate a clear clonal relationship. Our results support the hypothesis that UCBs following a primary surgically resected UTUC are predominantly clonally derived recurrences and not separate entities.

T1 Substaging of Nonmuscle Invasive Bladder Cancer is Associated with bacillus Calmette-Guérin Failure and Improves Patient Stratification at Diagnosis.

PURPOSE: Currently, markers are lacking that can identify patients with high risk nonmuscle invasive bladder cancer who will fail bacillus Calmette-Guérin treatment. Therefore, we evaluated the prognostic value of T1 substaging in patients with primary high risk nonmuscle invasive bladder cancer. MATERIALS AND METHODS: Patients with primary high risk nonmuscle invasive bladder cancer who received ≥5 bacillus Calmette-Guérin induction instillations were included. All tumors were centrally reviewed, which included T1 substaging (microinvasion vs extensive invasion of the lamina propria). T1 patients were stratified into high risk or highest risk subgroups according to major urology guidelines. Primary end point was bacillus Calmette-Guérin failure, defined as development of a high grade recurrence. Secondary end points were high grade recurrence-free survival, defined as time from primary diagnosis to biopsy-proven high grade recurrence and progression-free survival. Time-to-event analyses were used to predict survival. RESULTS: A total of 264 patients with high risk nonmuscle invasive bladder cancer had tumor invasion of the lamina propria, of which 73% were classified as extensive invasion and 27% as microinvasion. Median followup was 68 months (IQR 43-98) and bacillus Calmette-Guérin failure was more common among patients with extensive vs microinvasive tumors (41% vs 21%, p=0.002). The 3-year high grade recurrence-free survival (defined as bacillus Calmette-Guerin failure) for patients with extensive vs microinvasive tumors was 64% vs 83% (p=0.004). In multivariate analysis, T1 substaging was an independent predictor of high grade recurrence-free survival (HR 3.2, p=0.005) and progression-free survival (HR 3.0, p=0.009). Patients with highest risk/microinvasive disease have an improved progression-free survival as compared to highest risk/T1e disease (p.adj=0.038). CONCLUSIONS: T1 substaging provides important prognostic information on patients with primary high risk nonmuscle invasive bladder cancer treated with bacillus Calmette-Guérin. The risk of bacillus Calmette-Guérin failure is higher in extensive vs microinvasive tumors. Substaging of T1 high risk nonmuscle invasive bladder cancer has the potential to guide treatment decisions on bacillus Calmette-Guérin vs alternative strategies at diagnosis.

Risk factors associated with positive surgical margins' location at radical cystectomy and their impact on bladder cancer survival.

PURPOSE: To evaluate the risk factors associated with positive surgical margins' (PSMs) location and their impact on disease-specific survival (DSS) in patients with bladder cancer (BCa) undergoing radical cystectomy (RC). METHODS: We analyzed a large multi-institutional cohort of patients treated with upfront RC for non-metastatic (cT1-4aN0M0) BCa. Multivariable binomial logistic regression analyses were used to assess the risk of PSMs at RC for each location after adjusting for clinicopathological covariates. The Kaplan-Meier method was used to estimate DSS stratified by margins' status and location. Log-rank statistics and Cox' regression models were used to determine significance. RESULTS: A total of 1058 patients were included and 108 (10.2%) patients had PSMs. PSMs were located at soft-tissue, ureter(s), and urethra in 57 (5.4%), 30 (2.8%) and 21 (2.0%) patients, respectively. At multivariable analysis, soft-tissue PSMs were independently associated with pathological stage T4 (pT4) (Odds ratio (OR) 6.20, p < 0.001) and lymph-node metastases (OR 1.86, p = 0.04). Concomitant carcinoma-in-situ (CIS) was an independent risk factor for ureteric PSMs (OR 6.31, p = 0.003). Finally, urethral PSMs were independently correlated with pT4-stage (OR 5.10, p = 0.01). The estimated 3-years DSS rates were 58.2%, 32.4%, 50.1%, and 40.3% for negative SMs, soft-tissue-, ureteric- and urethral PSMs, respectively (log-rank; p < 0.001). CONCLUSIONS: PSMs' location represents distinct risk factors' patterns. Concomitant CIS was associated with ureteric PSMs. Urethral and soft-tissue PSM showed worse DSS rates. Our results suggest that clinical decision-making paradigms on adjuvant treatment and surveillance might be adapted based on PSM and their location.

Improving Anti-PD-1/PD-L1 Therapy for Localized Bladder Cancer.

In high-risk non-muscle invasive bladder cancer (HR-NMIBC), patient outcome is negatively affected by lack of response to Bacillus-Calmette Guérin (BCG) treatment. Lack of response to cisplatin-based neoadjuvant chemotherapy and cisplatin ineligibility reduces successful treatment outcomes in muscle-invasive bladder cancer (MIBC) patients. The effectiveness of PD-1/PD-L1 immune checkpoint inhibitors (ICI) in metastatic disease has stimulated its evaluation as a treatment option in HR-NMIBC and MIBC patients. However, the observed responses, immune-related adverse events and high costs associated with ICI have provided impetus for the development of methods to improve patient stratification, enhance anti-tumorigenic effects and reduce toxicity. Here, we review the challenges and opportunities offered by PD-1/PD-L1 inhibition in HR-NMIBC and MIBC. We highlight the gaps in the field that need to be addressed to improve patient outcome including biomarkers for response stratification and potentially synergistic combination therapy regimens with PD-1/PD-L1 blockade.

Biomarker-Oriented Therapy in Bladder and Renal Cancer.

Treatment of patients with urothelial carcinoma (UC) of the bladder or renal cancer has changed significantly during recent years and efforts towards biomarker-directed therapy are being investigated. Immune checkpoint inhibition (ICI) or fibroblast growth factor receptor (FGFR) directed therapy are being evaluated for non-muscle invasive bladder cancer (NMIBC) patients, as well as muscle-invasive bladder cancer (MIBC) patients. Meanwhile, efforts to predict tumor response to neoadjuvant chemotherapy (NAC) are still ongoing, and genomic biomarkers are being evaluated in prospective clinical trials. Currently, patients with metastatic UC (mUC) are usually treated with second-line ICI, while cisplatin-ineligible patients with programmed death-ligand 1 (PD-L1) positive tumors can benefit from first-line ICI. Platinum-relapsed UC patients harboring FGFR2/3 mutations can be treated with erdafitinib, while enfortumab vedotin has emerged as a novel third-line treatment option for mUC. In metastatic (clear cell) renal cell carcinoma (RCC), ICI was first introduced as second-line treatment after vascular endothelial growth factor receptor-tyrosine kinase inhibition (VEGFR-TKI). Currently, ICIs have also been introduced as first-line treatment in metastatic RCC. Although there is no evidence up to now for beneficial adjuvant treatment after surgery with VEGFR-TKIs in high-risk non-metastatic RCC, several trials are underway investigating the potential beneficial effect of ICIs in this setting.

Clinical Decision Making in Surveillance of Non-Muscle-Invasive Bladder Cancer: The Evolving Roles of Urinary Cytology and Molecular Markers.

Cystoscopy and urine cytology are the gold-standard tests for detection of recurrent disease during follow-up in patients with a history of non-muscle-invasive bladder cancer (NMIBC). High associated costs, as well as side effects, have driven the desire for inexpensive, noninvasive, accurate, and easy-to-use urine markers to detect bladder cancer recurrence. While many urine markers have been developed, very few have been clinically implemented. In this article, we discuss the requirements for development and validation of urine markers and the factors that hamper their clinical implementation. We also review current surveillance guidelines for NMIBC and provide an overview of approved urine markers for the detection and surveillance of NMIBC.

Molecular and clinical support for a four-tiered grading system for bladder cancer based on the WHO 1973 and 2004 classifications.

Currently, the use of two classification systems for bladder cancer grade is advocated in clinical guidelines because the WHO2004 classification has not been sufficiently validated with biological markers and follow-up. The slides of 325 primary non-muscle invasive bladder cancers from three hospitals were reviewed by one uro-pathologist in two separate sessions for the WHO1973 (G1, G2 and G3) and 2004 (papillary urothelial neoplasm of low malignant potential (LMP), low-grade (LG) and high-grade (HG)) classifications. FGFR3 status was examined with PCR-SNaPshot analysis. Expression of Ki-67, P53 and P27 was analyzed by immuno-histochemistry. Clinical recurrence and progression were determined. We performed validation and cross-validation of the two systems for grade with molecular markers and clinical outcome. Multivariable analyses were done to predict prognosis and pT1 bladder cancer. Grade review resulted in 88 G1, 149 G2 and 88 G3 lesions (WHO1973) and 79 LMP, 101 LG and 145 HG lesions (WHO2004). Molecular validation of both grading systems showed that FGFR3 mutations were associated with lower grades whereas altered expression (Ki-67, P53 and P27) was found in higher grades. Clinical validation showed that the two classification systems were both significant predictors for progression but not for recurrence. Cross-validation of both WHO systems showed a significant stepwise increase in biological (molecular markers) and clinical (progression) potential along the line: G1-LG-G2-HG-G3. The LMP and G1 categories had a similar clinical and molecular profile. On the basis of molecular biology and multivariable clinical data, our results support a four-tiered grading system using the 1973 and 2004 WHO classifications with one low-grade (LMP/LG/G1) category that includes LMP, two intermediate grade (LG/G2 and HG/G2) categories and one high-grade (HG/G3) category.

Are you sure it's an artifact? Artifact detection and uncertainty quantification in histological images.

Modern cancer diagnostics involves extracting tissue specimens from suspicious areas and conducting histotechnical procedures to prepare a digitized glass slide, called Whole Slide Image (WSI), for further examination. These procedures frequently introduce different types of artifacts in the obtained WSI, and histological artifacts might influence Computational Pathology (CPATH) systems further down to a diagnostic pipeline if not excluded or handled. Deep Convolutional Neural Networks (DCNNs) have achieved promising results for the detection of some WSI artifacts, however, they do not incorporate uncertainty in their predictions. This paper proposes an uncertainty-aware Deep Kernel Learning (DKL) model to detect blurry areas and folded tissues, two types of artifacts that can appear in WSIs. The proposed probabilistic model combines a CNN feature extractor and a sparse Gaussian Processes (GPs) classifier, which improves the performance of current state-of-the-art artifact detection DCNNs and provides uncertainty estimates. We achieved 0.996 and 0.938 F1 scores for blur and folded tissue detection on unseen data, respectively. In extensive experiments, we validated the DKL model on unseen data from external independent cohorts with different staining and tissue types, where it outperformed DCNNs. Interestingly, the DKL model is more confident in the correct predictions and less in the wrong ones. The proposed DKL model can be integrated into the preprocessing pipeline of CPATH systems to provide reliable predictions and possibly serve as a quality control tool.

Molecular biomarkers of progression in non-muscle-invasive bladder cancer - beyond conventional risk stratification.

The global incidence of bladder cancer is more than half a million diagnoses each year. Bladder cancer can be categorized into non-muscle-invasive bladder cancer (NMIBC), which accounts for ~75% of diagnoses, and muscle-invasive bladder cancer (MIBC). Up to 45% of patients with NMIBC develop disease progression to MIBC, which is associated with a poor outcome, highlighting a clinical need to identify these patients. Current risk stratification has a prognostic value, but relies solely on clinicopathological parameters that might not fully capture the complexity of disease progression. Molecular research has led to identification of multiple crucial players involved in NMIBC progression. Identified biomarkers of progression are related to cell cycle, MAPK pathways, apoptosis, tumour microenvironment, chromatin stability and DNA-damage response. However, none of these biomarkers has been prospectively validated. Reported gene signatures of progression do not improve NMIBC risk stratification. Molecular subtypes of NMIBC have improved our understanding of NMIBC progression, but these subtypes are currently unsuitable for clinical implementation owing to a lack of prospective validation, limited predictive value as a result of intratumour subtype heterogeneity, technical challenges, costs and turnaround time. Future steps include the development of consensus molecular NMIBC subtypes that might improve conventional clinicopathological risk stratification. Prospective implementation studies of biomarkers and the design of biomarker-guided clinical trials are required for the integration of molecular biomarkers into clinical practice.

Selecting the right treatment: Health outcome priorities in older patients with bladder cancer.

INTRODUCTION: Selecting the appropriate treatment for older patients with non-muscle invasive (NMIBC) or muscle-invasive bladder cancer (MIBC) is challenging due to smoking-related comorbidities, treatment toxicity, and an increased risk of adverse health outcomes. Considering patient preferences prior to treatment is therefore crucial. Here, we aimed to identify the health outcome priorities of older patients with high-risk NMIBC (HR-NMIBC) or MIBC. MATERIALS AND METHODS: Patients aged 70 years or older or at risk for frailty, diagnosed with HR-NMIBC or MIBC without distant metastases, were referred for a comprehensive geriatric assessment (CGA). The CGA consisted of an interview, physical examination, and several tests to examine physical, cognitive, functional, and social status. Quality of life was assessed using EQ5D and EORTC QLQ-C30 questionnaires. Health outcome priorities were discussed using the Outcome Prioritization Tool (OPT) and associations between health outcome priorities and CGA-determinants and quality of life were studied. RESULTS: Of 146 patients (14 HR-NMIBC, 132 MIBC), OPT data was available for 139. Life extension was most often prioritized (44%), closely followed by preserving independence (40%). Reducing pain (7%) and other symptoms (9%) were less often prioritized. Patients prioritizing life extension had fewer musculoskeletal problems than patients prioritizing reducing pain or other symptoms (p = 0.02). Patients at risk of or suffering from malnutrition more frequently selected reducing pain or other symptoms as their health outcome priority (p = 0.004). For all other CGA-determinants and quality of life, there were no significant differences between groups based on health outcome priorities. DISCUSSION: In older patients with HR-NMIBC and MIBC, life extension and preserving independence are the most common health outcomes priorities. CGA-determinants and quality of life are generally not associated with the prioritization of health outcomes. As health outcome priorities cannot be predicted by CGA-determinants or quality of life, it is crucial to discuss health outcome priorities with patients to promote shared decision-making.

The Diagnostic Accuracy of Cystoscopy for Detecting Bladder Cancer in Adults Presenting with Haematuria: A Systematic Review from the European Association of Urology Guidelines Office.

CONTEXT: Haematuria can be macroscopic (visible haematuria [VH]) or microscopic (nonvisible haematuria [NVH]), and may be caused by a number of underlying aetiologies. Currently, in case of haematuria, cystoscopy is the standard diagnostic tool to screen the entire bladder for malignancy. OBJECTIVE: The objective of this systematic review is to determine the diagnostic test accuracy of cystoscopy (compared with other tests, eg, computed tomography, urine biomarkers, and urine cytology) for detecting bladder cancer in adults. EVIDENCE ACQUISITION: A systematic review of the literature was performed according to the Cochrane Handbook for Systematic Reviews of Diagnostic Test Accuracy and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) extension for diagnostic test accuracy studies' checklist. The MEDLINE, Embase, Cochrane CENTRAL, and Cochrane CDSR databases (via Ovid) were searched up to July 13, 2022. The population comprises patients presenting with either VH or NVH, without previous urological cancers. Two reviewers independently screened all articles, searched reference lists of retrieved articles, and performed data extraction. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2). EVIDENCE SYNTHESIS: Overall, nine studies were included in the qualitative analysis. Seven out of nine included trials covered the use of cystoscopy in comparison with radiological imaging. Overall, sensitivity of cystoscopy ranged from 87% to 100%, specificity from 64% to 100%, positive predictive value from 79% to 98%, and negative predictive values between 98% and 100%. Two trials compared enhanced or air cystoscopy versus conventional cystoscopy. Overall sensitivity of conventional white light cystoscopy ranged from 47% to 100% and specificity from 93.4% to 100%. CONCLUSIONS: The true accuracy of cystoscopy for the detection of bladder cancer within the context of haematuria has not been studied extensively, resulting in inconsistent data regarding its performance for patients with haematuria. In comparison with imaging modalities, a few trials have prospectively assessed the diagnostic performance of cystoscopy, confirming very high accuracy for cystoscopy, exceeding the diagnostic value of any other imaging test. PATIENT SUMMARY: Evidence of tests for detecting bladder cancer in adults presenting with haematuria (blood in urine) was reviewed. The most common test used was cystoscopy, which remains the current standard for diagnosing bladder cancer.

Characterization of Fibroblast Growth Factor Receptor Alterations and Activation in Patients with High-Risk Non-Muscle Invasive Bladder Cancer.

PURPOSE: The GARNER study investigated fibroblast growth factor receptor (FGFR) alteration (ALT) frequency and the clinical outcome relationship with Bacillus Calmette-Guérin (BCG) treatment in high-risk non-muscle invasive bladder cancer (HR-NMIBC). An FGFR predictive response signature (FGFR-PRS) was discovered that identifies patients with an activated FGFR pathway who could potentially benefit from FGFR-targeted therapy beyond those who are FGFR ALT (+). EXPERIMENTAL DESIGN: Pre-treatment tumor samples and clinical data were analyzed from 582 BCG-treated HR-NMIBC patients. FGFR-PRS was discovered using a separate BC dataset and applied to the GARNER and other BC cohorts. FGFR-PRS was also applied to in vitro data from UC cell lines treated with FGFR-active agents. RESULTS: 31% of pre-treatment GARNER HR-NMIBC tumors were FGFR ALT (+) but this was not significantly associated with BCG response. For the subset of patients with paired pre- and post-BCG treatment samples, nearly one-third pre-treatment ALT (+) patients were ALT (-) post-treatment. FGFR-PRS identified patients with an activated FGFR pathway and identified approximately 2-fold additional patients compared to ALT status alone, and this increase was similar across tumor stage. A positive relationship between tumor growth inhibition and FGFR-PRS score was shown in BC in vitro models treated with FGFR-active agents. CONCLUSIONS: These data provide support for FGFR-targeted therapy use in FGFR ALT (+) HR-NMIBC and describe tumors with shared FGFR pathway-activated biology that are FGFR ALT (-) but FGFR-PRS (+). The latter suggests a broader potential patient population for FGFR-targeted therapy, which will require subsequent validation in patients treated with FGFR-targeted therapy.

A Genomic Urine Assay for Surveillance of Patients with Bladder Cancer Treated with Radiotherapy.

Background: Patients with muscle-invasive bladder cancer (MIBC) who receive radiotherapy with curative intent are followed by imaging, cystoscopy, and urine cytology. However, interpretation of cytology and cystoscopy is hampered by the impact of ionizing radiation on cells. Objective: To assess the diagnostic performance of a genomic urine assay to detect urinary tract recurrences in patients with MIBC treated by (chemo)radiation. Design setting and participants: Patients with nonmetastatic MIBC who underwent (chemo)radiation with curative intent from 2016 to 2020 were prospectively included. Follow-up consisted of cystoscopy and upper tract imaging. Prior to cystoscopy, a urine sample was analyzed to assess mutations in the genes FGFR3, HRAS, and TERT and methylation of OTX1, TWIST1, and ONECUT2. The treating physician was blinded for the assay result. Outcome measurements and statistical analysis: The primary endpoint was a urinary tract recurrence. Cross-sectional sensitivity, specificity, and negative predictive value (NPV) were analyzed using a previously developed logistic regression model for the detection of bladder cancer with this assay. The secondary endpoint was the risk of a future urinary tract recurrence following a positive test and negative cystoscopy/imaging, using a time-dependent Cox proportional hazard analysis. Results and limitations: A total of 143 patients were included, and 503 urine samples were analyzed. The median study duration was 20 mo (interquartile range [IQR] 10-33), and the median time to a recurrence was 16 mo (IQR 12-26). In 27 patients, 32 urinary tract recurrences were diagnosed, including three upper tract tumors. Of 32 recurrences, 18 (56%) had a concomitant urine test available. The diagnostic model had an area under the curve of 0.80 (95% confidence interval [CI] 0.69-0.90) with corresponding sensitivity, specificity, and NPV of 78 (95% CI 52-94), 77% (95% CI 73-81), and 99% (95% CI 97-100). When taking into account the anticipatory effect of the test, 28/32 (88%) recurrences were detected. A Cox regression analysis showed a hazard ratio of 14.8 for the development of a future recurrence (p < 0.001). A major limitation was the lack of a concomitant urine test result in 14/32 (44%) recurrences. Conclusions: A genomic urine assay detected urinary tract recurrences after (chemo)radiation in patients with MIBC, and a positive test was strongly associated with future recurrences. Although validation in a large cohort is warranted, the test has the potential to limit frequent cystoscopies. Patient summary: Radiotherapy is a bladder-sparing treatment in patients with bladder cancer. After treatment, these patients undergo visual inspection of the bladder by cystoscopy to detect possible recurrences. However, interpretation of cystoscopy is difficult due to the effects of radiation on the bladder lining. Hence, we analyzed the diagnostic value of a molecular urine test to detect recurrent disease in bladder cancer patients treated by radiotherapy, and we showed that the urine test has the potential to limit the number of cystoscopies.

NPEPPS Is a Druggable Driver of Platinum Resistance.

There is an unmet need to improve the efficacy of platinum-based cancer chemotherapy, which is used in primary and metastatic settings in many cancer types. In bladder cancer, platinum-based chemotherapy leads to better outcomes in a subset of patients when used in the neoadjuvant setting or in combination with immunotherapy for advanced disease. Despite such promising results, extending the benefits of platinum drugs to a greater number of patients is highly desirable. Using the multiomic assessment of cisplatin-responsive and -resistant human bladder cancer cell lines and whole-genome CRISPR screens, we identified puromycin-sensitive aminopeptidase (NPEPPS) as a driver of cisplatin resistance. NPEPPS depletion sensitized resistant bladder cancer cells to cisplatin in vitro and in vivo. Conversely, overexpression of NPEPPS in sensitive cells increased cisplatin resistance. NPEPPS affected treatment response by regulating intracellular cisplatin concentrations. Patient-derived organoids (PDO) generated from bladder cancer samples before and after cisplatin-based treatment, and from patients who did not receive cisplatin, were evaluated for sensitivity to cisplatin, which was concordant with clinical response. In the PDOs, depletion or pharmacologic inhibition of NPEPPS increased cisplatin sensitivity, while NPEPPS overexpression conferred resistance. Our data present NPEPPS as a druggable driver of cisplatin resistance by regulating intracellular cisplatin concentrations. SIGNIFICANCE: Targeting NPEPPS, which induces cisplatin resistance by controlling intracellular drug concentrations, is a potential strategy to improve patient responses to platinum-based therapies and lower treatment-associated toxicities.

Multi-Center Assessment of Lymph-Node Density and Nodal-Stage to Predict Disease-Specific Survival in Patients with Bladder Cancer Treated by Radical Cystectomy.

BACKGROUND: Prognostic tools in pathological-node (pN) patients after radical cystectomy (RC) are needed. OBJECTIVES: To evaluate the prognostic impact of lymph node (LN)-density on disease-specific survival (DSS) in patients with bladder cancer (BC) undergoing RC with pelvic lymph node dissection. METHODS: We analyzed a multi-institutional cohort of 1169 patients treated with upfront RC for cT1-4aN0M0 urothelial BCat nine centers. LN-densitywas calculated as the ratio of the number of positive LNs×100% to the number of LNs removed. The optimal LN-density cut-off value was defined by creating a time-dependent receiver operating characteristic (ROC) curve in pN patients. Univariable and multivariable Cox' regression analyses were used to assess the effect of conventional Tumor Nodes Metastasis (TNM) nodal staging system, LN-density and other LN-related variables on DSS in the pN-positive cohort. RESULTS: Of the 1169 patients, 463 (39.6%) patients had LN-involvement. The area under the ROC curve was 0.60 and the cut-off for LN-density was set at 20%, 223 of the pN-positive patients (48.2%) had a LN-density ≥ 20%. In multivariable models, the number of LN-metastases (HR 1.03, p = 0.005) and LN-density, either as continuous (HR 1.01, p = 0.013) or as categorical variable (HR 1.37, p = 0.014), were independently associated with worse DSS, whereas pN-stage was not. CONCLUSIONS: LN-density ≥ 20% was an independent predictor of worse DSS in BC patients with LN-involvement at RC. The integration of LN-density and other LN-parameters rather than only conventional pN-stage may contribute to a more refined risk-stratification in BC patients with nodal involvement.

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.

FGFR3 mutation analysis in voided urine samples to decrease cystoscopies and cost in nonmuscle invasive bladder cancer surveillance: a comparison of 3 strategies.

PURPOSE: We determined whether FGFR3 mutation analysis of voided urine samples would be cost-effective to partly replace cystoscopy in the surveillance of patients treated for nonmuscle invasive urothelial carcinoma. MATERIALS AND METHODS: In this decision analytical study we analyzed data on 70 Dutch patients with FGFR3 positive primary tumors and a median followup of 8.8 years. Surveillance strategies were compared in a Markov model. Modified surveillance consisted of FGFR3 mutation analysis of voided urine samples every 3 months, and cystoscopy at 3, 12 and 24 months. Standard surveillance was defined as cystoscopy every 3 months and minimal surveillance was defined as cystoscopy at 3, 12 and 24 months. Analysis was stratified for 3 risk profiles, including surveillance after 1) the primary tumor, 2) the first to third recurrence and 3) the fourth recurrence or more. Sensitivity analysis was performed to evaluate the impact of variations in cost, sensitivity and specificity. RESULTS: The probability of no recurrence after 2 years of surveillance after a primary tumor was higher for modified surveillance than for standard and minimal surveillance, eg after primary tumors (95.7% vs 95.0% and 93.9%, respectively). The total cost of surveillance after the primary tumor was lower for minimal and modified surveillance (€2,254 and €2,558, respectively) than for standard surveillance (€5,861). Results were robust to changing inputs over plausible ranges and consistent for each of the 3 risk profiles. CONCLUSIONS: Surveillance in which cystoscopy is partly replaced by FGFR3 mutation analysis of urine seems a safe, effective and cost-effective surveillance strategy. Further validation in larger cohorts is required.