Comparative differences between T1a/b and T1e/m as substages in T1 urothelial carcinoma of the bladder

A Systematic Review on the Current Landscape of T1 Bladder Cancer Substaging

OBJECTIVE

To conduct a systematic review on the current state of T1 bladder tumor substaging. These neoplasms display significant heterogeneity in oncological behavior and prognosis, leading to the proposal of various substaging methods. Our aim was to investigate the potential diagnostic and prognostic value of substaging in stage T1 bladder cancer for better oncologic outcomes.

METHODS

A literature search using MEDLINE, EMBASE and Cochrane Library databases was conducted in March 2024 to identify relevant studies on T1 urothelial bladder cancer staging. A systematic review of included articles was performed following the PRISMA guideline statement. Literature search was conducted in English.

RESULTS

Overall, 63 studies published between 1990 and 2024 were included for final review including a total number of 8207 bladder tumor patients subject to T1 substaging. Various substaging methods have been developed, broadly classified into histometric (anatomy-based) and micrometric (semiquantitative) techniques. Advanced stages have been consistently associated with worse prognosis and need for a more radical therapeutic approach. A standardized, validated, unified substaging report system is lacking.

CONCLUSIONS

T1 substaging is a strong predictor of oncologic outcomes. Micrometric methods seem to be more reproducible and precise than histometric techniques in terms of feasibility and prognostic value. Standardization and validation of the technique could potentially enhance the bladder cancer treatment algorithm. We would like to provide an explanation regarding why our systematic review was not prospectively registered in the PROSPERO database. Initially, this review was conceived as part of a doctoral thesis (PhD) project, and there was no intention to publish it. Although we strictly adhered to the PRISMA guidelines from the beginning, the decision to publish the review was made only after most of the data had been extracted. At that point, retrospectively registering it in PROSPERO would have been somewhat unethical, which is why we chose not to register it. We fully recognize the importance of actively registering systematic reviews, as it is the proper and ethical way to proceed in these cases. We remain committed to transparency and best practices in research and believe that prospective registration is crucial for ensuring the integrity and credibility of systematic reviews.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer: Working Group 3: Subcategorization of T1 Bladder Cancer

Emerging data on T1 bladder cancer subcategorization (aka substaging) suggests a correlation with oncological outcomes. The International Society of Urological Pathology (ISUP) organized the 2022 consensus conference in Basel, Switzerland to focus on current issues in bladder cancer and tasked working group 3 to make recommendations for T1 subcategorization in transurethral bladder resections. For this purpose, the ISUP developed and circulated a survey to their membership querying approaches to T1 bladder cancer subcategorization. In particular, clinical relevance, pathological reporting, and endorsement of T1 subcategorization in the daily practice of pathology were surveyed. Of the respondents of the premeeting survey, about 40% do not routinely report T1 subcategory. We reviewed literature on bladder T1 subcategorization, and screened selected articles for clinical performance and practicality of T1 subcategorization methods. Published literature offered evidence of the clinical rationale for T1 subcategorization and at the conference consensus (83% of conference attendants) was obtained to report routinely T1 subcategorization of transurethral resections. Semiquantitative T1 subcategorization was favored (37%) over histoanatomic methods (4%). This is in line with literature findings on practicality and prognostic impact, that is, a shift of publications from histoanatomic to semiquantitative methods or by reports incorporating both methodologies is apparent over the last decade. However, 59% of participants had no preference for either methodology. They would add a comment in the report briefly stating applied method, interpretation criteria (including cutoff), and potential limitations. When queried on the terminology of T1 subcategorization, 34% and 20% of participants were in favor of T1 (microinvasive) versus T1 (extensive) or T1 (focal) versus T1 (nonfocal), respectively.

Combination of Two T1 Substaging Systems (T1a/b/c and T1m/e) Better Predicts Tumor Outcomes in Patients with T1 High Grade Bladder Cancer

BACKGROUND

T1 substaging is a predictive factor for non-muscle-invasive bladder cancer, and two types of T1 substaging systems (T1a/b/c and T1m/e) are currently in use. However, the predictive ability of both systems is poor, and there is debate over which system is better.

OBJECTIVE

To confirm whether combination of two T1 substaging systems can improve the predictive ability of T1 substaging for tumor outcomes.

METHODS

Patients with primary pT1 high-grade bladder cancer from three centers were included. All tumors were assessed with T1a/b/c and T1m/e substaging. A new variable named COMB was developed in which patients were stratified into T1a/b&T1m, T1a/b&T1e, T1c&T1m or T1c&T1e subgroups. A time-dependent receiver operating characteristic curve (ROC) analysis was used to test whether the accuracy of prediction could be improved with COMB.

RESULTS

A total of 239 patients with primary pT1HG were analyzed. No tumor was T1c&T1m, and therefore, only three types of combinations were evaluated: T1a/b&T1m (62 patients), T1a/b&T1e (124 patients) and T1c&T1e (53 patients). Regardless of all patients or those treated with Re-TURBt and adequate BCG, patients with T1a/b&T1m have the best prognosis, and those with T1c&T1e have the poorest prognosis. The time-dependent ROC showed that, for both recurrence and progression, COMB had a higher AUC than T1a/b/c and T1m/e, regardless of population.

CONCLUSIONS

Compared with either system alone, the combination of two T1 substaging systems improves the predictive ability of T1 substaging for tumor outcomes.

The Genitourinary Pathology Society Update on Classification of Variant Histologies, T1 Substaging, Molecular Taxonomy, and Immunotherapy and PD-L1 Testing Implications of Urothelial Cancers

The Genitourinary Pathology Society (GUPS) undertook a critical review of the recent advances in bladder cancer focusing on important topics of high interest for the practicing surgical pathologist and urologist. This review represents the second of 2 manuscripts ensuing from this effort. Herein, we address the effective reporting of bladder cancer, focusing particularly on newly published data since the last 2016 World Health Organization (WHO) classification. In addition, this review focuses on the importance of reporting bladder cancer with divergent differentiation and variant (subtypes of urothelial carcinoma) histologies and the potential impact on patient care. We provide new recommendations for reporting pT1 staging in diagnostic pathology. Furthermore, we explore molecular evolution and classification, emphasizing aspects that impact the understanding of important concepts relevant to reporting and management of patients.

Substaging of pT1 Urothelial Bladder Carcinoma Predicts Tumor Progression and Overall Survival

INTRODUCTION

Limitations in tumor staging and the heterogeneous natural evolution of pT1 urothelial bladder carcinoma (UBC) make the choice of treatment challenging. We evaluated if histopathological substaging (pT1a, pT1b, and pT1c) helps predict disease recurrence, progression, and overall survival following transurethral resection of the bladder (TURB).

METHODS

We included 239 consecutive patients diagnosed with pT1 UBC at TURB in a single institution since 2001. Each sample was interpreted by our specialized uropathologists trained to subclassify pT1 stage. Three groups were distinguished according to the degree of invasion: T1a (up to the muscularis mucosae [MM]), T1b (into the MM), and T1c (beyond the MM).

RESULTS

T1 substaging was possible in 217/239 (90%) patients. pT1a, b, and c occurred in 124 (57), 59 (27), and 34 (16%), respectively. The median follow-up was 3.1 years, with a cumulative recurrence rate of 52%, progression rate of 20%, and survival rate of 54%. Recurrence was not significantly associated with tumor substage (p = 0.61). However, the Kaplan-Meier survival analysis showed a significantly higher progression rate among T1b (31) and T1c (26%) tumors than T1a (13%) (log-rank test: p = 0.001) stages. In a multivariable model including gender, age, ASA score, smoking, tumor grade, and presence of carcinoma in situ, T1 substage was the single variable significantly associated with progression-free survival (HR 1.7, p = 0.005). Nineteen patients (9%) needed radical cystectomy; among them, 12/19 (63%) had an invasive tumor. Overall survival was significantly associated with tumor substaging (p = 0.001).

CONCLUSION

Histopathological substaging of pT1 UBC is significantly associated with tumor progression and overall survival and therefore appears to be a useful prognostic tool to counsel patients about treatment options.

Prognosis of patients with T1 bladder cancer after en bloc transurethral resection of bladder tumor stratified by invasion to the level of the muscularis mucosa

PURPOSE

To evaluate the prognosis of patients with pT1 bladder cancer who underwent en bloc resection of bladder tumors (ERBTs), stratified by invasion to the muscularis mucosa (MM) level.

METHODS

Among 64 specimens obtained by ERBT with bipolar energy from patients with pT1 bladder cancer, MM was detected in 61 specimens. Thus, 61 specimens were included in this retrospective study. Patients were stratified by invasion to the MM level (pT1a, invasion above the MM level; pT1b, invasion within the MM level; and pT1c, invasion beyond the MM level). In specimens with discontinuous MM, invasion to the MM level was predicted from the dispersed MM in the specimen. The primary endpoints were progression-free survival (PFS) and cancer-specific survival (CSS).

RESULTS

Progression occurred in 2/39 patients with pT1a (5.1%), 1/6 patients with pT1b (16.7%), and 6/16 patients with pT1c cancer (37.5%). Cancer death occurred in 1/39 patients with pT1a (2.6%), 0/7 patients with pT1b, and 3/16 patients with pT1c cancer (18.8%). Patients with pT1a or pT1b cancer had a significantly better prognosis than those with pT1c cancer. On univariate analysis, tumor size ≥ 3 cm and pT1c were significantly associated with shorter PFS. On multivariate analysis, only pT1c was independently associated with shorter PFS.

CONCLUSION

This is the first study evaluating the prognosis by T1 substaging based on invasion to the MM level using ERBT specimens. ERBT provided high-quality specimens for diagnosing the MM and showed poor prognosis in pT1c bladder cancer. ERBT could be an appropriate surgical approach for an accurate diagnosis and prognosis of the T1 bladder cancer substage.

The impact of tumor invasion to muscularis mucosaevascular plexus on patient outcome in pT1 bladder urothelial carcinoma

OBJECTIVES

T1 bladder cancer has a wide range of tumor behavior and lamina propria invasion depth has a high potential risk of disease progression. To evaluate the patient outcome according to the tumor invasion to the muscularis mucosae-vascular plexus (MM-VP) in pT1 bladder urothelial carcinoma (BUC).

MATERIALS AND METHODS

This study is a retrospective analysis of patients consecutively recorded from 2007 to 2013. A total of 93 patients with a history of primary pT1 BUC and complete follow-up were included. We used a pathological substaging system according to the tumor invasion regarding the MM-VP: pT1a (invasion above MM-VP) and pT1b (MM-VP invasion). We evaluated recurrence-free survival (RFS), progression- free survival (PFS), disease-specific-survival (DSS) based on this sub-staging system.

RESULTS

Pathological evaluation regarding the MM-VP invasion revealed 53 patients (57%) as pT1a BUC and 40 patients (43%) as pT1b BUC. The mean follow-up was 78.8 months. During the follow-up period; 60 patients (64.5%) had tumor recurrences, 32 patients (34.4%) had progression to invasive disease, 18 patients (19.4 %) died during follow-up related to the BUC. In 29 (54.7%) of pT1a and in 31(77.5%) of pT1b tumors, the recurrent disease was recorded during the followup period (p = 0.023). DSS rates at 5 years for pT1a and pT1b were 80.2% and 60.8%, respectively. PFS, RFS, and DSS rates were similar for pT1a/pT1b and did not reach statistical significance (p > 0.05).

CONCLUSIONS

Sub-staging of pT1 BUC according to the MM-VP invasion showed a limited impact on the outcome in our patient cohort. However, the presence of pT1b disease caused a significantly higher rate of recurrence.

Sub-Staging-Specific Differences in Recurrence-Free, Progression-Free, and Cancer-Specific Survival for Patients with T1 Bladder Cancer: A Systematic Review and Meta-Analysis

INTRODUCTION

The efficiency of the T1 sub-staging system on categorizing bladder cancer (BC) patients into subgroups with different clinical outcomes was unclear. We summarized relevant evidences, including recurrence-free survival (RFS), progression-free survival (PFS), and cancer-specific survival (CSS), to analyze the prognostic significance of T1 sub-stage.

METHODS

Systematic literature searches of MEDLINE, EMBASE, and the Cochrane Library were performed. We pooled data on recurrence, progression, and CSS from 35 studies.

RESULTS

The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) indicated the difference in RFS between T1a sub-stage and T1b sub-stage (HR 1.28, 95% CI 1.14-1.43, p < 0.001). The significant difference was observed in PFS between the 2 arms (HR 2.18, 95% CI 1.95-2.44, p < 0.001). Worse CSS was found in T1b patients than in T1a patients (HR 1.36, 95% CI 1.21-1.54, p < 0.001).

CONCLUSIONS

T1 sub-staging system based on the invasion depth into muscularis mucosae can be a significant prognostic factor for RFS, PFS, and CSS of patients with T1 BC. Urologists and pathologists are encouraged to work together to give a precise sub-stage classification of T1 BC, and T1 sub-staging system should be a routine part of any histopathological report when possible. Different treatment strategies need to be developed for both T1a BC and T1b BC.

Prognostic value of T1 substaging on oncological outcomes in patients with non-muscle-invasive bladder urothelial carcinoma: a systematic literature review and meta-analysis

Purpose

To evaluate the prognostic value of substaging on oncological outcomes in patients with T (or pT1) urothelial carcinoma of the bladder.

Methods

A literature search using PubMed, Scopus, Web of Science, and Cochrane Library was conducted on March 2019 to identify relevant studies according to the Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) guidelines. The pooled disease recurrence (DR) and disease progression (DP) rate in T1(or pT1) patients were calculated using a fixed or random effects model.

Results

Overall 36 studies published between 1994 and 2018 including a total of 6781 bladder cancer patients with T1(or pT1) stage were selected for the systematic review and meta-analysis. Twenty-nine studies reported significant association between tumor infiltration depth or muscularis mucosa (MM) invasion and oncological outcomes. Totally 12 studies were included in the meta-analysis. MM invasion (T1a/b/c [or pT1a/b/c] or T1a/b [or pT1a/b] substaging system) was associated with DR (pooled HR: 1.23, 95%CI: 1.01–1.49) and DP (pooled HR: 2.61, 95%CI: 1.61–4.23). Tumor infiltration depth (T1 m/e [or pT1 m/e] substaging system) was also associated with DR (pooled HR: 1.49, 95%CI: 1.11–2.00) and DP (pooled HR: 3.29, 95%CI: 2.39–4.51).

Conclusions

T1(or pT1) substaging in patients with bladder cancer is of prognostic value as it is associated with oncologic outcomes. Inclusion of this factors into the clinical decision-making process of this heterogeneous tumor may improve outcomes, while avoiding over- and under-treatment for T1(or pT1) bladder cancer.

Clinical significance and effect of MTDH/AEG-1 in bladder urothelial cancer: a study based on immunohistochemistry, RNA-seq, and in vitro verification

Background

Overexpression of metadherin/astrocyte elevated gene-1 (MTDH/AEG-1) has been implicated in various cancers. However, the clinical significance and the potential biological functions of MTDH/AEG-1 in bladder urothelial carcinoma (BUC) are not established.

Methods

In this study, the expression of MTDH/AEG-1in BUC was measured using the Cancer Genome Atlas (TCGA) database and immunohistochemistry, together with a meta-analysis, to investigate the expression and diagnostic value of MTDH/AEG-1. The possible association between MTDH/AEG-1 expression and the viability, proliferation, and apoptosis in BUC cell lines (T24, HT1376, and RT4) was also assessed in vitro by viability, MTS, colony formation, and caspase-3/7 assays, as well as Hoechst 33342 and propidium iodide (PI) double staining.

Results

MTDH/AEG-1 expression was significantly higher in BUC tissues than in normal bladder tissues, according to the TCGA and immunohistochemistry results, and these findings were verified by the meta-analysis. Functional knockdown of MTDH/AEG-1 suppressed BUC cell growth and induced apoptosis. Bioinformatics analyses indicated an involvement of MTDH/AEG-1 in several processes, including RNA binding, protein transport, intracellular transport, and the insulin signaling pathway.

Conclusion

We hypothesize that MTDH/AEG-1 could play essential roles in BUC, especially in cell growth and apoptosis, via the insulin signaling pathway.”