An interobserver reproducibility study on invasiveness of bladder cancer using virtual microscopy and heatmaps

A single-center retrospective comparison of pT1 substaging methods in bladder cancer

Substaging of T1 urothelial cancer is associated with tumor progression and its reporting is recommended by international guidelines. However, it has not been integrated in risk stratification tools and there is no agreement on the best method to use for its reporting. We aimed to investigate the applicability, interobserver variability, and prognostic value of histological landmark based and micrometric (aggregate linear length of invasive carcinoma (ALLICA), microscopic vs. extensive system, Rete Oncologica Lombarda (ROL) system) substaging methods. A total of 79 patients with the primary diagnosis of T1 urothelial cancer treated with conventional transurethral resection and adjuvant BCG therapy between 2000 and 2020 at the Medical University of Vienna were included. The anatomical and metrical substaging systems were evaluated using agreement rate, Cohen's kappa, Kendall's tau, and Spearman rank correlation. Prognostic value for high-grade recurrence or T2 progression was evaluated in uni- and multivariable analysis. Applicability and reproducibility were good to moderate and varied between substaging methods. Obstacles are mainly due to fragmentation of samples. Anatomical substaging was associated with progression in univariable and multivariable analysis. In our cohort, we could only identify anatomical landmark-based substaging to be prognostic for T2 progression. A major obstacle for proper pathological assessment is fragmentation of samples due to operational procedure. Avoiding such fragmentation might improve reproducibility and significance of pathological T1 substaging of urothelial cancer.

Stromal and Epithelial Architectural Alterations Mimicking Invasion (Pseudoinvasion) in Noninvasive Papillary Urothelial Carcinoma

CONTEXT.—

Retraction artifact, paradoxic maturation/differentiation, desmoplasia, and complex irregular growth are morphologic criteria of invasion in urothelial carcinoma.

OBJECTIVE.—

To describe changes mimicking invasion in noninvasive papillary urothelial carcinoma (NPUC).

DESIGN.—

We reviewed 159 consecutive in-house patients with NPUC for either the presence of pseudoinvasion (irregular carcinoma nests within dense hyalinized stroma in the absence of other criteria of invasion) or precursor findings (stromal hyalinization not yet associated with epithelial architectural alteration). We assessed the correlation of these findings with age, sex, evidence of peripheral vascular disease, tumor grade, tumor infarction, and tumor size. We then followed up the patients clinically for tumor recurrence or progression.

RESULTS.—

We identified 233 separate NPUCs (136 high grade and 97 low grade) in 125 men and 34 women. Of the 233 tumors, 26 (11.2%) had pseudoinvasion and 24 of 233 tumors (10.3%) had precursor findings. Except for complex irregular growth, no other criteria for invasion were seen. Pseudoinvasion and precursor findings were more common in men (47 of 183 [26%] versus 3 of 50 [6%]; P = .003), larger tumors (mean size, 2.6 versus 1.2 cm; P < .001), and tumors with infarction (33 of 50 [66%] versus 29 of 183 [15.8%]; P < .001). In multivariable analysis, tumor size (odds ratio, 1.49; P =.006), male sex (odds ratio, 6.48; P = .007), and the presence of infarction (odds ratio, 6.59; P < .001) were significant variables. Recurrence rates did not differ between patients with and those without pseudoinvasion (31% [5 of 16] versus 42% [45 of 107], respectively; P = .41). None of the tumors with pseudoinvasion progressed to invasive carcinoma.

CONCLUSIONS.—

Given the correlation with size and presence of infarcted papillae, we suggest the possibility of tumor ischemia/infarction as a plausible etiology of pseudoinvasion. Awareness of this phenomenon is important for the accurate diagnosis of invasion in papillary urothelial carcinoma.

European Association of Urology Guidelines on Non-muscle-invasive Bladder Cancer (TaT1 and Carcinoma In Situ)-A Summary of the 2024 Guidelines Update

BACKGROUND AND OBJECTIVE

This publication represents a summary of the updated 2024 European Association of Urology (EAU) guidelines for non-muscle-invasive bladder cancer (NMIBC), TaT1, and carcinoma in situ. The information presented herein is limited to urothelial carcinoma, unless specified otherwise. The aim is to provide practical recommendations on the clinical management of NMIBC with a focus on clinical presentation.

METHODS

For the 2024 guidelines on NMIBC, new and relevant evidence was identified, collated, and appraised via a structured assessment of the literature. Databases searched included Medline, EMBASE, and the Cochrane Libraries. Recommendations within the guidelines were developed by the panel to prioritise clinically important care decisions. The strength of each recommendation was determined according to a balance between desirable and undesirable consequences of alternative management strategies, the quality of the evidence (including the certainty of estimates), and the nature and variability of patient values and preferences.

KEY FINDINGS AND LIMITATIONS

Key recommendations emphasise the importance of thorough diagnosis, treatment, and follow-up for patients with NMIBC. The guidelines stress the importance of defining patients' risk stratification and treating them appropriately.

CONCLUSIONS AND CLINICAL IMPLICATIONS

This overview of the 2024 EAU guidelines offers valuable insights into risk factors, diagnosis, classification, prognostic factors, treatment, and follow-up of NMIBC. These guidelines are designed for effective integration into clinical practice.

Predicting non-muscle invasive bladder cancer outcomes using artificial intelligence: a systematic review using APPRAISE-AI

Accurate prediction of recurrence and progression in non-muscle invasive bladder cancer (NMIBC) is essential to inform management and eligibility for clinical trials. Despite substantial interest in developing artificial intelligence (AI) applications in NMIBC, their clinical readiness remains unclear. This systematic review aimed to critically appraise AI studies predicting NMIBC outcomes, and to identify common methodological and reporting pitfalls. MEDLINE, EMBASE, Web of Science, and Scopus were searched from inception to February 5th, 2024 for AI studies predicting NMIBC recurrence or progression. APPRAISE-AI was used to assess methodological and reporting quality of these studies. Performance between AI and non-AI approaches included within these studies were compared. A total of 15 studies (five on recurrence, four on progression, and six on both) were included. All studies were retrospective, with a median follow-up of 71 months (IQR 32-93) and median cohort size of 125 (IQR 93-309). Most studies were low quality, with only one classified as high quality. While AI models generally outperformed non-AI approaches with respect to accuracy, c-index, sensitivity, and specificity, this margin of benefit varied with study quality (median absolute performance difference was 10 for low, 22 for moderate, and 4 for high quality studies). Common pitfalls included dataset limitations, heterogeneous outcome definitions, methodological flaws, suboptimal model evaluation, and reproducibility issues. Recommendations to address these challenges are proposed. These findings emphasise the need for collaborative efforts between urological and AI communities paired with rigorous methodologies to develop higher quality models, enabling AI to reach its potential in enhancing NMIBC care.

Prospective Validation of the ROL System in Substaging pT1 High-Grade Urothelial Carcinoma: Results from a Mono-Institutional Confirmatory Analysis in BCG Treated Patients

Patients with pT1 high-grade (HG) urothelial carcinoma (UC) and a very high risk of progression might benefit from immediate radical cystectomy (RC), but this option remains controversial. Validation of a standardized method to evaluate the extent of lamina propria (LP) invasion (with recognized prognostic value) in transurethral resection (TURBT) specimens is still needed. The Rete Oncologica Lombarda (ROL) system showed a high predictive value for progression after TURBT in recent retrospective studies. The ROL system was supposed to be validated on a large prospective series of primary urothelial carcinomas from a single institution. From 2016 to 2020, we adopted ROL for all patients with pT1 HG UC on TURBT. We employed a 1.0-mm threshold to stratify tumors in ROL1 and ROL2. A total of 222 pT1 HG UC were analyzed. The median age was 74 years, with a predominance of men (73.8%). ROL was feasible in all cases: 91 cases were ROL1 (41%), and 131 were ROL2 (59%). At a median follow-up of 26.9 months (IQR 13.8-40.6), we registered 81 recurrences and 40 progressions. ROL was a significant predictor of tumor progression in both univariable (HR 3.53; CI 95% 1.56-7.99; p < 0.01) and multivariable (HR 2.88; CI 95% 1.24-6.66; p = 0.01) Cox regression analyses. At Kaplan-Meier estimates, ROL showed a correlation with both PFS (p = 0.0012) and RFS (p = 0.0167). Our results confirmed the strong predictive value of ROL for progression in a large prospective series. We encourage the application of ROL for reporting the extent of LP invasion, substaging T1 HG UC, and improving risk tables for urological decision-making.

Evaluation of grade and invasiveness of bladder urothelial carcinoma using infrared imaging and machine learning

Urothelial bladder carcinoma (BC) is primarily diagnosed with a subjective examination of biopsies by histopathologists, but accurate diagnosis remains time-consuming and of low diagnostic accuracy, especially for low grade non-invasive BC. We propose a novel approach for high-throughput BC evaluation by combining infrared (IR) microscopy of bladder sections with machine learning (partial least squares-discriminant analysis) to provide an automated prediction of the presence of cancer, invasiveness and grade. Cystoscopic biopsies from 50 patients with clinical suspicion of BC were histologically examined to assign grades and stages. Adjacent tissue cross-sections were IR imaged to provide hyperspectral datasets and cluster analysis segregated IR images to extract the average spectra of epithelial and subepithelial tissues. Discriminant models, which were validated using repeated random sampling double cross-validation, showed sensitivities (AUROC) ca. 85% (0.85) for the identification of cancer in epithelium and subepithelium. The diagnosis of non-invasive and invasive cases showed sensitivity values around 80% (0.84-0.85) and 76% (0.73-0.80), respectively, while the identification of low and high grade BC showed higher sensitivity values 87-88% (0.91-0.92). Finally, models for the discrimination between cancers with different invasiveness and grades showed more modest AUROC values (0.67-0.72). This proves the high potential of IR imaging in the development of ancillary platforms to screen bladder biopsies.

Urothelial Carcinoma: Update on Staging and Reporting, and Pathologic Changes Following Neoadjuvant Chemotherapies

Staging and reporting of cancers of the urinary tract have undergone major changes in the past decade to meet the needs for improved patient management. Substantial progress has been made. There, however, remain issues that require further clarity, including the substaging of pT1 tumors, grading and reporting of tumors with grade heterogeneity, and following NAC. Multi-institutional collaborative studies with prospective data will further inform the accurate diagnosis, staging, and reporting of these tumors, and in conjunction with genomic data will ultimately contribute to precision and personalized patient management.

[Interpretation of biopsy material after transuretral and laser en bloc resection of non-muscle-invasive bladder cancer]

Bladder cancer is one of the most common onco-urological diseases, ranked second in frequency among all tumors of the urinary system after prostate cancer. At the time of detection of the primary tumor, approximately 75% of patients have no invasion into the muscularis layer (non-muscle-invasive carcinoma), with tumor growth limited to the basal membrane (stage Ta) or submucosal base (stage T1). Removal of the tumor in a «unified block» (laser en-bloc resection or L-ERBT), unlike routine transurethral resection, allows to obtain qualitative biopsy material for precise pathomorphological staging of the tumor process. In order to accurately stratify a patient into one or another risk group, verification of the following morphological parameters is required: degree of tumor differentiation and its malignancy, depth of invasion, foci of carcinoma in situ at resection margins, presence or absence of lymphovascular invasion. Identification of tumor variant histology is also recommended. Information on presence or absence of detrusor elements in the specimen is necessary in the morphological report, as this parameter is considered as a criterion of radically performed tumor removal. According to ICCR recommendations (International Collaboration on cancer reporting), it is recommended to use subclassification of T1 stage using all possible criteria: volume and/or depth of invasion (assessed in mm), and/or width of invasion «spot» (assessed in mm), and/or involvement of anatomical structure - muscularis mucosae. Full morphological examination of the material obtained during the primary resection of the tumor is an important step in the diagnosis and treatment of bladder cancer, as it allows to stratify the patient into one or another risk group and, accordingly, allows to develop a personalized postoperative management.

Bladder Cancer Sample Handling and Reporting: Pathologist's Point of View

The aim of this narrative review is to provide adequate information on handling and reporting of the bladder cancer samples to improve the closely collaboration between pathologists and urologists. The main (but not exclusive) research tool used was PubMed and 87 references were selected and quoted in the text. We have considered handling of biopsies, transurethral resection (TUR), and cystectomy specimens to summarize the different methods of sampling and the related issues. Moreover, we considered and discussed the main prognostic factors, such as histological tumor type, grade, and stage of bladder cancer, that should be described in the pathological report. In addition, critical issues encountered in the interpretation of histological samples were discussed.

Updated pathology reporting standards for bladder cancer: biopsies, transurethral resections and radical cystectomies

Aim

Optimal management of bladder cancer requires an accurate, standardised and timely pathological diagnosis, and close communication between surgeons and pathologists. Here, we provide an update on pathology reporting standards of transurethral resections of the bladder and cystectomies.

Methods

We reviewed recent literature, focusing on developments between 2013 and 2021.

Results

Published reporting standards developed by pathology organizations have improved diagnosis and treatment. Tumor sub-staging and subtyping has gained increased attention. Lymph nodes continue to be an area of debate, and their staging has seen minor modifications. Several tasks, particularly regarding specimen preparation (“grossing”), are not yet standardized and offer opportunity for improvement. Molecular classification is rapidly evolving, but currently has only limited impact on management.

Conclusion

Pathological reporting of bladder cancer is continuously evolving and remains challenging in some areas. This review provides an overview of recent major developments, with a particular focus on published reporting standards.

Stage T1 bladder cancer: diagnostic criteria and pitfalls

Accurate pathological staging is crucial for patient management. Patients with T1 bladder cancer are at risk of recurrence, progression, and death of cancer. Recognition of early invasion (stage T1 disease) in urothelial carcinoma remains one of the most challenging areas in urological surgical pathology practice. A logical roadmap to T1 diagnosis would include careful evaluation of histological grade, stromal epithelial interface, characteristics of the invading epithelium, and the stroma associated responses. Tangential sectioning, crush and cautery artifacts, and associated inflammatory infiltrate are commonly encountered problems and the source of pitfalls. In this review, we outline diagnostic criteria, common pitfalls, and different histological patterns of invasion into the lamina propria. Current recommendations on reporting of biopsy and transurethral resection specimens, molecular biomarkers, clinical implications of T1 cancer diagnosis and recent developments on the T1 substaging are also discussed. Most T1 bladder cancer patients will benefit from conservative management after restaging transurethral resection of bladder and bacillus Calmette-Guérin maintenance. Patients with high risk features, such as concurrent urothelial carcinoma in situ, increased depth of invasion, lymphovascular invasion, and variant histology among others, should be considered for early cystectomy.

pT1 high-grade bladder cancer: histologic criteria, pitfalls in the assessment of invasion, and substaging

Most patients with bladder carcinoma are diagnosed with non-muscle-invasive disease, stage Ta, and pT1. Stage remains as the single most important prognostic indicator in urothelial carcinoma. Among the pT1 bladder cancer patients, recurrence and progression of disease occur in 50% and 10%, respectively. The identification of high-risk patients within the pT1 subgroup remains an important clinical goal and an active field of research. Substaging of pT1 disease has been claimed as important histologic discriminator by the 2016 World Health Organization (WHO) classification of the genitourinary tract tumors and by the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual supporting its implementation in clinical practice. Interobserver variation in pT1 diagnosis and the associated pitfalls in pT1 assessment are the critical pathological issues. The aim of this review paper is to provide the practicing pathologist with the state of the art of morphological and immunohistochemical features useful for the diagnosis of early invasive bladder carcinomas, including practical clues on how to avoid relevant interpretative pitfalls, and to summarize the current status of pT1 substaging.

Dataset for the reporting of urinary tract carcinoma-biopsy and transurethral resection specimen: recommendations from the International Collaboration on Cancer Reporting (ICCR)

The International Collaboration on Cancer Reporting (ICCR) is an alliance of major pathology organisations in Australasia, Canada, Europe, United Kingdom, and United States of America that develops internationally standardised, evidence-based datasets for the pathology reporting of cancer specimens. This dataset was developed by a multidisciplinary panel of international experts based on previously published ICCR guidelines for the production of cancer datasets. It is composed of Required (core) and Recommended (noncore) elements identified on the basis of literature review and expert consensus. The document also includes an explanatory commentary explaining the rationale behind the categorization of individual data items and provides guidance on how these should be collected and reported. The dataset includes nine required and six recommended elements for the reporting of cancers of the urinary tract in biopsy and transurethral resection (TUR) specimens. The required elements include specimen site, operative procedure, histological tumor type, subtype/variant of urothelial carcinoma, tumor grade, extent of invasion, status of muscularis propria, noninvasive carcinoma, and lymphovascular invasion (LVI). The recommended elements include clinical information, block identification key, extent of T1 disease, associated epithelial lesions, coexistent pathology, and ancillary studies. The dataset provides a structured template for globally harmonized collection of pathology data required for management of patients diagnosed with cancer of the urinary tract in biopsy and TUR specimens. It is expected that this will facilitate international collaboration, reduce duplication of effort in updating current national/institutional datasets, and be particularly useful for countries that have not developed their own datasets.

A validation study of whole slide imaging for primary diagnosis of lymphoma

Whole slide imaging (WSI) is being increasingly used worldwide. Although previous studies have asserted the validity of WSI diagnosis, they have primarily targeted only small specimens and excluded cases requiring immunohistochemistry or special staining, such as lymphoma. The purpose of this study was to evaluate the accuracy of WSI diagnosis of lymphoma, for which 240 biopsies and resections of lymphoma cases were selected from the study set of lymphomas. All slides including H&E, immunohistochemical and special staining were digitized using a WSI image scanner. An experienced pathologist performed the WSI diagnoses, which were compared with original diagnoses based on light microscopic examinations. Discrepancy between the two interpretations were classified into three categories: concordance, minor discrepancy (no clinical significance), and major discrepancy (with clinical significance). Overall concordance between the light microscopic and WSI diagnosis was found in 223 cases (92.92%; 95%CI = 88.90-95.82), minor discrepancy in fifteen (6.25%; 95%CI = 3.54-10.10), and major discrepancy in two (0.83%; 95%CI = 0.10-2.98). Diagnosis of lymphoma using WSI appeared to be mostly accurate, suggesting that WSI may be a reliable technology for the diagnosis of lymphoma.

A paired kappa to compare binary ratings across two medical tests

Agreement between experts' ratings is an important prerequisite for an effective screening procedure. In clinical settings, large-scale studies are often conducted to compare the agreement of experts' ratings between new and existing medical tests, for example, digital versus film mammography. Challenges arise in these studies where many experts rate the same sample of patients undergoing two medical tests, leading to a complex correlation structure between experts' ratings. Here, we propose a novel paired kappa measure to compare the agreement between the binary ratings of many experts across two medical tests. Existing approaches can accommodate only a small number of experts, rely heavily on Cohen's kappa and Scott's pi measures of agreement, and thus are prone to their drawbacks. The proposed kappa appropriately accounts for correlations between ratings due to patient characteristics, corrects for agreement due to chance, and is robust to disease prevalence and other flaws inherent in the use of Cohen's kappa. It can be easily calculated in the software package R. In contrast to existing approaches, the proposed measure can flexibly incorporate large numbers of experts and patients by utilizing the generalized linear mixed models framework. It is intended to be used in population-based studies, increasing efficiency without increasing modeling complexity. Extensive simulation studies demonstrate low bias and excellent coverage probability of the proposed kappa under a broad range of conditions. Methods are applied to a recent nationwide breast cancer screening study comparing film mammography to digital mammography.

Three-dimensional histopathological reconstruction of bladder tumours

BACKGROUND

Histopathological analysis is the cornerstone in bladder cancer (BCa) diagnosis. These analysis suffer from a moderate observer agreement in the staging of bladder cancer. Three-dimensional reconstructions have the potential to support the pathologists in visualizing spatial arrangements of structures, which may improve the interpretation of specimen. The aim of this study is to present three-dimensional (3D) reconstructions of histology images.

METHODS

En-bloc specimens of transurethral bladder tumour resections were formalin fixed and paraffin embedded. Specimens were cut into sections of 4 μm and stained with Hematoxylin and Eosin (H&E). With a Phillips IntelliSite UltraFast scanner, glass slides were digitized at 20x magnification. The digital images were aligned by performing rigid and affine image alignment. The tumour and the muscularis propria (MP) were manually delineated to create 3D segmentations. In conjunction with a 3D display, the results were visualized with the Vesalius3D interactive visualization application for a 3D workstation.

RESULTS

En-bloc resection was performed in 21 BCa patients. Per case, 26-30 sections were included for the reconstruction into a 3D volume. Five cases were excluded due to export problems, size of the dataset or condition of the tissue block. Qualitative evaluation suggested an accurate registration for 13 out of 16 cases. The segmentations allowed full 3D visualization and evaluation of the spatial relationship of the BCa tumour and the MP.

CONCLUSION

Digital scanning of en-bloc resected specimens allows a full-fledged 3D reconstruction and analysis and has a potential role to support pathologists in the staging of BCa.

Harmonization in laboratory medicine: more than clinical chemistry?

The goal of harmonizing laboratory information is to contribute to quality in patient care, ultimately improving upon patient outcomes and safety. The main focus of harmonization and standardization initiatives has been on analytical processes within the laboratory walls, clinical chemistry tests in particular. However, two major evidences obtained in recent years show that harmonization should be promoted not only in the analytical phase but also in all steps of the testing process, encompassing the entire field of laboratory medicine, including innovative areas (e.g. “omics”) rather than just conventional clinical chemistry tests. A large body of evidence demonstrates the vulnerability of the extra-analytical phases of the testing cycle. Because only “good biological samples” can assure good analytical quality, a closer interconnection between the different phases of the cycle is needed. In order to provide reliable and accurate laboratory information, harmonization activities should cover all steps of the cycle from the “pre-pre-analytical” phase (right choice of test at right time for right patient) through the analytical steps (right results with right report) to the “post-post-analytical” steps (right and timely acknowledgment of laboratory information, right interpretation and utilization with any necessary advice as to what to do next with the information provided). In addition, modern clinical laboratories are performing a broad menu of hundreds of tests, covering both traditional and innovative subspecialties of the discipline. In addition, according to a centered viewpoint, harmonization initiatives should not be addressed exclusively to clinical chemistry tests but should also include all areas of laboratory medicine.

SIU-ICUD on bladder cancer: pathology

Many changes have been made during these last years and concepts for understanding bladder cancer have evolved. We make an update with the latest findings of the WHO (World Health Organistaion) 2016, ICCR (International Collaboration on Cancer Reporting) and other official organisms and try to show the latest developments. In this document we provide new consensus guidelines and insights. We kept this document short and concise providing consensus guidelines to clinicians for the best patient care, it should be easy to understand for a non pathologists. We focussed on several burning issues, such as the anatomical and histological understanding of the bladder wall, the prognostic significance of grading and the most challenging problems in staging, we underline our needs from the clinicians such as clinical information, we further discuss the histological subtypes of bladder cancer, which is an extremely important issue in the light of molecular classifications and give prognostic insights. Furthermore, we discuss the ICCR worldwide consensus reporting, urinary cytology with the Paris system and several issues such as frozen section specimen.

Contribution of bladder cancer pathology assessment in planning clinical trials

Bladder cancer is a heterogeneous disease that demonstrates a wide spectrum of histologic features. The modern classification of bladder cancer is largely based on pathologic analysis, which assesses tumor grade, stage, type, size, and other features that are essential for understanding the biological behavior of bladder cancer. Bladder cancers with similar histologic features are likely to show comparable responses to a new therapeutic agent in clinical trial. Furthermore, pathologic analysis also evaluates the quality of tissue samples in clinical trial to ensure the integrity of various molecular tests. In spite of the emerging role of genomic and molecular studies, pathology remains the cornerstone in the diagnosis, prognosis, and treatment of bladder cancer. Herein, the pathologic considerations for bladder cancer clinical trial planning are reviewed.

A practical guide to bladder cancer pathology

Pathological assessment of bladder cancer is becoming an increasingly complex task owing to the growing availability of molecular data for different histological subtypes and the appreciation of their importance in determining outcomes of neoadjuvant chemotherapy. Urologists are aware of the need to closely collaborate with pathologists, and comprehensive sharing of information is crucial to achieve optimal patient management. Numerous steps towards this goal have been made during the past years. Important advances in the assessment and reporting of grading and staging, especially substaging of pT1 urothelial carcinomas, have been made. As part of the International Collaboration on Cancer Reporting (ICCR), an international expert group has suggested worldwide reporting standards for urothelial lesions. Nevertheless, several issues remain unresolved, for example, regarding the reporting of heterogeneous lesions and substaging as well as the gross handling and the reporting for lymphadenectomy specimens. During the past few years, major insights have been gained into the molecular changes that occur during bladder cancer development, but a consensus on how to integrate these data into daily practice has not been achieved.

Significance of Ki-67 in non-muscle invasive bladder cancer patients: a systematic review and meta-analysis

Purpose

This meta-analysis evaluated the prognostic significance of Ki-67 in non-muscle invasive bladder cancer (NMIBC).

Materials and Methods

We selected 39 articles including 5,229 patients from Embase, Scopus, and PubMed searches. The primary outcomes, recurrence-free survival (RFS), progression-free survival (PFS), disease-specific survival (DSS), and overall survival (OS) were determined using time-to event hazard ratios (HRs) with 95% confidence intervals (CIs). Study heterogeneity was tested by chi-square and I² statistics. Heterogeneity sources were identified by subgroup meta-regression analysis.

Results

Two studies were prospective; 37 were retrospective. Immunohistochemistry was performed in tissue microarrays or serial sections. A wide range of antibody dilutions and Ki-67 positivity thresholds were used. Study heterogeneity was attributed to analysis results in studies of RFS (p < 0.0001). Meta-regression analysis revealed that region and analysis results accounted for heterogeneity in PFS studies (p = 0.00471, p < 0.0001). High Ki-67 expression was associated with poor RFS (pooled HR, 1.78; 95% CI, 1.48–2.15), poor PFS (pooled HR, 1.28; 95% CI, 1.13–2.15), poor DSS (pooled HR, 2.24; 95% CI, 1.47–2.15), and worse OS (pooled HR, 2.29; 95% CI, 1.24–4.22).

Conclusions

The meta-analysis found that current evidence supports the prognostic value of Ki-67 in NMIBC patients.

Challenges in Pathologic Staging of Bladder Cancer: Proposals for Fresh Approaches of Assessing Pathologic Stage in Light of Recent Studies and Observations Pertaining to Bladder Histoanatomic Variances

The paradigm of pathologic stage (pT) categorization in bladder cancer remains the depth of invasion into the different histologic layers of the bladder wall. However, the approaches to assigning pT stage category toward an enhanced outcome stratification have been marked by challenges and innovations, due in part to our growing appreciation of the surprisingly perplexing bladder histoanatomy. Upstaging of pT1 tumors after radical cystectomy is substantial and underscores the potential value of pT1 substaging in transurethral resection (TUR) specimens. The 2017 American Joint Committee on Cancer tumor-node-metastasis system recommends pT1 substaging but recognizes the need to optimize the approach. Over the years, the cut-off for microinvasion has been significantly lowered to 0.5 mm and is now a promising scheme for pT1 (micrometric) substaging. Unlike the micrometric approach, histoanatomic substaging using muscularis mucosae (MM) and vascular plexus as landmarks is less feasible in TUR specimens and inconsistent in stratifying the outcome of pT1 tumors. The lamina propria possesses inherent variations in depth, MM, and vascular plexus dispositions that should be factored in future pT1 substaging proposals. Histoanatomic variations among the bladder regions also occur, and studies suggest that trigone and bladder neck cancers may have more adverse outcomes. The muscularis propria (MP), besides being the essential histologic landmark for assigning pT2 stage category, is also considered a surrogate for the adequacy of TUR, furthering the importance of identifying its presence in TUR specimens. MP, however, may be mimicked by hyperplastic or isolated MP-like MM muscle bundles in the lamina propria with overstaging implications, and caution should be exercised in distinguishing these 2 muscle types morphologically and immunohistochemically. Presence of additional superficial MP unique from the detrusor muscle proper may also complicate staging at the trigone and ureter insertion sites. With regard to the depth of MP invasion, large and multicenter studies have reaffirmed the prognostic significance of pT2a/b subcategories. It is revealed that there are at least 3 ways used to demarcate the irregular MP to perivesical soft tissue junction, and use of a common criterion indicates improvement in pT2b/pT3a staging reproducibility. Although studies have shown significantly poorer outcome in pT3b compared with pT3a tumors, this designation has a substantial reliance on the prosector's gross assessment of perivesical soft tissue invasion which if performed incorrectly may lead to staging inaccuracy of pT3 tumors. The 8th edition of the American Joint Committee on Cancer has updated the staging schema for bladder cancers with concomitant prostatic stromal invasion and cancers within bladder diverticula. Because of 2 possible pT designations, prostatic stromal invasion in TUR specimens should not be automatically staged as either pT4a or pT2 (urethral). Recent data support that bladder cancer invading into the seminal vesicle has comparable outcome to pT4b tumors. Interestingly, several studies in pT4a tumors, which are staged based on sex-specific organs, have shown poorer outcome in females than males after radical cystectomy, and while there are possibly several reasons, they may also include anatomic factors. Despite the progress has been made, work remains to be done to inform future bladder cancer pT category definitions and their reproducibility in application and prognostication.

Usefulness of pT1 substaging in papillary urothelial bladder carcinoma

Background

When treating bladder cancer patients, the most significant problems usually concern cases with high-grade non-muscle-invasive carcinoma, and a better understanding of which patients would benefit from early radical cystectomy is urgently needed. The uropathology community is seeking more user-friendly approaches to distinguishing between T1 cancers exhibiting different types of clinical behavior.

Methods

After a retrospective review, we selected a group of 314 patients who underwent transurethral resection of the bladder (TURB) and were diagnosed with high-grade urothelial carcinoma staged as T1. Three different substaging systems were applied: one was the anatomy-based T1 a/b; and two involved micrometric thresholds of either 0.5 mm of invasion (as proposed by van Rhijn et al.), or 1 mm of invasion (as proposed in the present study). Early reTUR (repeated transurethral resection) was performed in 250 patients, and the same substaging approaches were applied to cases of T1.

Results

It proved feasible to apply the 1 mm substaging system in 100 % of cases, the van Rhijn system in 100 %, and the anatomy-based method (T1 a/b) in 72.3 % of cases. At a mean follow-up of 46 months, the recurrence-free survival rate was significantly better (p < 0.001) in the group that underwent reTUR, while none of the three substaging systems reliably predicted recurrences. The 1 mm did seem promising, however, as a threshold for predicting progression, reaching statistical significance in the Kaplan Meier estimates (p < 0.04).

Conclusion

Our study shows that micrometric substaging is feasible in this setting and should be extended to include any early reTUR to complete the substaging done after the first TURB. It can also provide helpful prognostic information.

Quality of diagnostic staging in patients with bladder cancer: a process-outcomes link

BACKGROUND

Muscle sampling is often used as a surrogate for staging quality in patients with bladder cancer. The association of staging quality at diagnosis and survival was examined among patients with bladder cancer.

METHODS

The clinical records of all individuals within the Los Angeles Surveillance, Epidemiology, and End Results registry with an incident diagnosis of non-muscle-invasive bladder cancer in 2004-2005 were reviewed. Patient demographics, tumor characteristics, staging quality (presence of muscle in the specimen and mention of muscle in the pathology report), and vital status were recorded. With mixed-effects and competing-risks regression analyses, the association of patient and tumor characteristics with staging quality and cancer-specific survival was quantified.

RESULTS

The sample included 1865 patients, 335 urologists, and 27 pathologists. Muscle was reported to be present in 972 (52.1%), was reported to be absent in 564 (30.2%), and was not mentioned in 329 (17.7%) of the initial pathology reports. The presence of muscle did not differ according to the grade or depth of invasion. Mortality was associated with staging quality (P < .05). Among patients with high-grade disease, the 5-year cancer-specific mortality rates were 7.6%, 12.1%, and 18.8% when muscle was present, absent, and not mentioned, respectively.

CONCLUSIONS

The omission of muscle in the specimen or its mention in the pathology report in nearly half of all diagnostic resections was associated with increased mortality, particularly in patients with high-grade disease. Because urologists cannot reliably discern between high- and low-grade or Ta and T1 disease, it is contended that patients with bladder cancer should undergo adequate muscle sampling at the time of endoscopic resection.

Validation of whole slide imaging in the primary diagnosis of gynaecological pathology in a University Hospital

AIMS

Experience in the use of whole slide imaging (WSI) for primary diagnosis in pathology is very limited. We aimed to determine the accuracy of interpretation of WSI compared with conventional light microscopy (CLM) in the diagnosis of routine gynaecological biopsies.

METHODS

All gynaecological specimens (n=452) received over a 2-month period at the Department of Pathology of the Hospital Clinic of Barcelona were analysed blindly by two gynaecological pathologists, one using CLM and the other WSI. All slides were digitised in a Ventana iScan HT (Roche diagnostics) at 200×. All discrepant diagnoses were reviewed, and a final consensus diagnosis was established. The results were evaluated by weighted κ statistics for two observers.

RESULTS

The level of interobserver agreement between WSI and CLM evaluations was almost perfect (κ value: 0.914; 95% CI 0.879 to 0.949) and increased during the study period: κ value 0.890; 95% CI 0.835 to 0.945 in the first period and 0.941; 95%; CI 0.899 to 0.983 in the second period. Major discrepancies (differences in clinical management or prognosis) were observed in 9 cases (2.0%). All discrepancies consisted of small lesions (8 high grade squamous intraepithelial lesions of the uterine cervix, one lymph node micrometastasis of an ovarian carcinoma) underdiagnosed or missed in the WSI or the CLM evaluation. Discrepancies with no or minor clinical relevance were identified in 3.8% of the biopsies. No discrepancy was related to the poor quality of the WSI image.

CONCLUSIONS

Diagnosis of gynaecological specimens by WSI is accurate and may be introduced into routine diagnosis.