Quantifying the effect of color processing on blood and damaged tissue detection in Whole Slide Images

Histological tissue examination has been a longstanding practice for cancer diagnosis where pathologists identify the presence of tumors on glass slides. Slides acquired from laboratory routine may contain unintentional artifacts due to complications in surgical resection. Blood and damaged tissue artifacts are two common problems associated with transurethral resection of the bladder tumor. Differences in histotechnical procedures among laboratories may also result in color variations and minor inconsistencies in outcome. A digitized version of a glass slide known as a whole slide image (WSI) holds enormous potential for automated diagnostics. The presence of irrelevant areas in a WSI undermines diagnostic value for pathologists as well as computational pathology (CPATH) systems. Therefore, automatic detection and exclusion of diagnostically irrelevant areas may lead to more reliable predictions. In this paper, we are detecting blood and damaged tissue against diagnostically relevant tissue. We gauge the effectiveness of transfer learning against training from scratch. Best models give 0.99 and 0.89 F1 scores for blood and damaged tissue detection. Since blood and damaged tissue have subtle color differences, we assess the impact of color processing methods on the binary classification performance of five well-known architectures. Finally, we remove the color to understand its importance against morphology on classification performance.acceptedVersio

Invasive cancerous area detection in non-muscle invasive bladder cancer whole slide images

Bladder cancer patients’ stratification into risk groups relies on grade, stage and clinical factors. For non-muscle invasive bladder cancer, T1 tumours that invade the subepithelial tissue are high-risk lesions with a high probability to progress into an aggressive muscle-invasive disease. Detecting invasive cancerous areas is the main factor for dictating the treatment strategy for the patient. However, defining invasion is often subject to intra/interobserver variability among pathologists, thus leading to over or undertreatment. Computer-aided diagnosis systems can help pathologists reduce overheads and erratic reproducibility. We propose a multi-scale model that detects invasive cancerous areas patterns across the whole slide image. The model extracts tiles of different tissue types at multiple magnification levels and processes them to predict invasive patterns based on local and regional information for accurate T1 staging. Our proposed method yields an F1 score of 71.9, in controlled settings 74.9, and without infiltration 90.0.acceptedVersio

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.publishedVersio

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

In-depth investigation of the molecular pathogenesis of bladder cancer in a unique 26-year old patient with extensive multifocal disease: A case report

Background. The molecular characteristics and the clinical disease course of bladder cancer (BC) in young patients remain largely unresolved. All patients are monitored according to an intensive surveillance protocol and we aim to gain more insight into the molecular pathways of bladder tumors in young patients that could ultimately contribute to patient stratification, improve patient quality of life and reduce associated costs. We also determined whether a biomarker-based surveillance could be feasible. Case Presentation. We report a unique case of a 26-year-old Caucasian male with recurrent non-muscle invasive bladder tumors occurring at a high frequency and analyzed multiple tumors (maximal pTaG2) and urine samples of this patient. Analysis included FGFR3 mutation detection, FGFR3 and TP53 immunohistochemistry, mircosatellite analysis of markers on chromosomes 8, 9, 10, 11 and 17 and a genome wide single nucleotide polymorphism-array (SNP). All analyzed tumors contained a mutation in FGFR3 and were associated with FGFR3 overexpression. None of the tumors showed overexpression of TP53. We found a deletion on chromosome 9 in the primary tumor and this was confirmed by the SNP-array that showed regions of loss on chromosome 9. Detection of all recurrences was possible by urinary FGFR3 mutation analysis. Conclusions. Our findings would suggest that the BC disease course is determined by not only a patient's age, but also by the molecular characteristics of a tumor. This young patient contained typical genetic changes found in tumors of older patients and implies a clinical disease course comparable to older patients. We demonstrate that FGFR3 mutation analysis on voided urine is a simple non-invasive method and could serve as a feasible follow-up approach for this young patient presenting with an FGFR3 mutant tumor

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

PD-L1 Antibody Comparison in Urothelial Carcinoma

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Artificial Intelligence in Digital Pathology for Bladder Cancer: Hype or Hope? A Systematic Review

Bladder cancer (BC) diagnosis and prediction of prognosis are hindered by subjective pathological evaluation, which may cause misdiagnosis and under-/over-treatment. Computational pathology (CPATH) can identify clinical outcome predictors, offering an objective approach to improve prognosis. However, a systematic review of CPATH in BC literature is lacking. Therefore, we present a comprehensive overview of studies that used CPATH in BC, analyzing 33 out of 2285 identified studies. Most studies analyzed regions of interest to distinguish normal versus tumor tissue and identify tumor grade/stage and tissue types (e.g., urothelium, stroma, and muscle). The cell’s nuclear area, shape irregularity, and roundness were the most promising markers to predict recurrence and survival based on selected regions of interest, with >80% accuracy. CPATH identified molecular subtypes by detecting features, e.g., papillary structures, hyperchromatic, and pleomorphic nuclei. Combining clinicopathological and image-derived features improved recurrence and survival prediction. However, due to the lack of outcome interpretability and independent test datasets, robustness and clinical applicability could not be ensured. The current literature demonstrates that CPATH holds the potential to improve BC diagnosis and prediction of prognosis. However, more robust, interpretable, accurate models and larger datasets—representative of clinical scenarios—are needed to address artificial intelligence’s reliability, robustness, and black box challenge

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