T1 bladder carcinoma with variant histology: pathological features and clinical significance

Giant cell carcinoma of the urinary bladder : Clinicopathologic analysis and oncological outcomes

We present the clinicopathological features of 23 cases of the giant cell subtype of urothelial carcinoma, a rare subtype of bladder cancer recognized in the current World Health Organization classification of urological tumors. Histologically, the architectural pattern of the tumor varied from infiltrating to the solid expansile pleomorphic tumor with giant, bizarre, anaplastic cells. Typical or atypical mitotic figures were frequently present in all cases. Between 10 and 30% of the tumor had a giant cell component. All cases were associated with conventional high-grade urothelial carcinoma, with areas of squamous cell divergent differentiation and micropapillary carcinoma present in six and two cases, respectively. In one case each had sarcomatoid, nested, small cell, or glandular divergent differentiation. At diagnosis, 35% of patients had advanced disease and 12% had distant metastases. When comparing giant cell urothelial carcinoma with conventional urothelial carcinoma in a matched analysis, differences in overall and cancer-specific survival were observed, particularly in the T1 stage category. Immunohistochemical staining showed a similar profile of urothelial lineage with frequent positive expression of uroplakin II, GATA3, CK20, CK7, and S100P in both giant cell and conventional urothelial carcinomas. High Ki67 proliferation (range, 60-90%; mean, 71%) and nuclear p53 accumulation (mutant profile; range, 50-90%; mean, 64%) were observed. Using the 22C3 assay, the expression of PD-L1 was found to be variable in two cases, and beta-HCG was negative. In conclusion, giant cell carcinoma is a subtype of urothelial carcinoma associated with advanced clinical stage and a trend to lower survival rates.

Influence of lamina propria invasion extension on T1 high-grade non-muscle-invasive bladder cancer in patients undergoing BCG or radical cystectomy

OBJECTIVE

To evaluate the prognostic value of T1 substaging in patients treated with bacillus Calmette-Guérin (BCG) or immediate radical cystectomy (iRC).

MATERIALS AND METHODS

We performed an institutional review board-approved retrospective study analysing non-muscle-invasive bladder cancer (NMIBC) patients with pT1 disease treated with either BCG or iRC between 2000 and 2020. Lamina propria (LP) invasion characteristics were extracted from the pathology report. The Kaplan-Meier method was used to calculate overall survival (OS), cancer-specific survival (CSS) and metastasis-free survival (MFS). Multivariable Cox models were used to determine the association between progression-free survival (PFS) and characteristics in the BCG cohort. A logistic regression model explored the relationship between T1 substaging and upstaging to >pT2 at iRC.

RESULTS

A total of 411 T1 high-grade patients were identified. LP invasion characteristics were as follows: not specified: 115 (28%); focal/superficial (F/S): 147 (35.8%); and extensive/multifocal (E/M): 149 (36.2%). Overall, 303 patients (73.7%) received BCG, and 108 patients (26.3%) underwent iRC. The median (interquartile range) follow-up was 53 (32-96) months. Patients with E/M LP invasion were significantly more likely to undergo iRC (34% vs. 19%; P = 0.003). Patients with E/M LP invasion showed poorer MFS and CSS compared to those with F/S LP invasion when treated with BCG but not when treated with iRC. Among BCG-treated patients, progression occurred in 41 patients and E/M LP invasion was independently associated with progression after BCG (hazard ratio 5.3, 95% confidence interval [CI] 2.2-13.1; P < 0.001). T1 substaging was not associated with upstaging at RC (odds ratio 3.15, 95% CI 0.82-12.12; P = 0.095).

CONCLUSIONS

Extensive/multifocal LP invasion was associated with poor PFS, MFS and CSS in patients treated with BCG. T1 substaging provides valuable prognostic information and should be reported in pathology reports.

A meta-analysis of UCA1 accuracy in the detection of bladder cancer

INTRODUCTION

Bladder cancer (BCa) exhibits a relatively high prevalence, yet convenient tools for its early detection are lacking. Our study aims to assess the diagnostic value of Urothelial Carcinoma-Associated 1 (UCA1) in the early detection of BCa.

METHODS

Systematic searches were performed in electronic databases (PubMed, Web of Science, Science Direct, CNKI, Wanfang, and VIP) until 20 July 2023. QUADAS-2 was used for quality assessment, while Meta-DiSc 1.4 and STATA 14.0 were employed for statistical analysis.

RESULTS

A total of 1252 BCa patients and 779 controls, from 12 identified articles, were included. UCA1 showed strong discriminatory ability in BCa detection, with an overall sensitivity of 0.84 specificity of 0.91, and a 0.91 area under the curve (AUC). Strikingly, UCA1 expressed in urine and tissue exhibited higher diagnostic value (0.92 AUC) compared to that in blood (0.86 AUC). Furthermore, urine UCA1 demonstrated remarkable diagnostic performance with 91% sensitivity and 98% specificity. Deeks' funnel plot detected no substantial publication bias.

CONCLUSION

UCA1 could serve as a potential biomarker for BCa detection with good diagnostic performance. Besides, compared to UCA1 in blood, urine and tissue UCA1 exhibited higher diagnostic value. Further prospective clinical research is needed to corroborate the conclusion.

PROSPERO REGISTRATION

CRD42023463210.

Impact of variant histology on upstaging and survival in patients with nonmuscle invasive bladder cancer undergoing radical cystectomy

INTRODUCTION

Variant histology (VH) of urothelial carcinoma is uncommon and frequently presents at the muscle-invasive stage. VH is considering a significant risk factor for progression among patients with nonmuscle invasive bladder cancer (NMIBC). While there is some debate, expert opinion is generally that upfront radical cystectomy (RC) should be consider for these patients. Limited data exists to support this position. In this study, we sought to examine the rate of upstaging and overall survival for patients with VH NMIBC against patients with pure urothelial NMIBC who underwent RC, to help clarify the optimal treatment strategy for these patients.

METHODS

The institutional REDCap database was utilized to identify all patients with T1 and Ta bladder cancer that underwent RC over the study period (2004-2022). Matched-pair analysis was performed between patients with VH and pure urothelial NMIBC; 42 pairs were matched on prior intravesical therapy, presence of muscularis propria on transurethral resection of bladder tumor (TURBT), any carcinoma in situ presence on prior TURBTs, and final tumor staging on TURBT. The primary outcomes of interest were pathologic tumor upstaging rate at RC and overall survival. Secondary outcomes of interest included association of demographic or pretreatment variables with upstaging, and upstaging rates for specific variant histologies.

RESULTS

Patients with VH NMIBC undergoing RC were upstaged at a significantly higher rate than a matched cohort of patients with pure urothelial NMIBC (73.8% vs. 52.4%, P = 0.0244) and among those upstaged, had significantly higher rates of pT3 to pT4 (54.7% vs. 23.8%, P = 0.0088). Rate of node positivity at RC for VH NMIBC was also higher compared to pure urothelial NMIBC (40.5% vs. 21.4%, P = 0.0389). Among histologic variants, patients with plasmacytoid and sarcomatoid subtypes demonstrated the highest rates of upstaging; differences were not statistically significant. The overall median survival was 28.4 months for patients with VH after RC compared to 155.1 months for patients with pure urothelial NMIBC (P = 0.009).

CONCLUSION

Patients with VH NMIBC undergoing RC are at significantly higher risk of upstaging at RC when compared to patients with pure urothelial NMIBC and have worse overall survival. While this study supports the concept of an aggressive treatment approach for patients with VH NMIBC, improvements in understanding of the disease are necessary to improve outcomes.

Targeted multiparametric magnetic resonance imaging/transrectal ultrasound-guided (mpMRI/TRUS) fusion prostate biopsy versus systematic random prostate biopsy: A comparative real-life study

BACKGROUND

Patients with suspected prostate cancer usually undergo transrectal ultrasound-guided (TRUS) systematic biopsy, which can miss relevant prostate cancers and lead to overtreatment.

AIMS

The aim of this study was to evaluate the detection rate for prostate cancer in MR-guided targeted biopsy (TB) and systematic biopsy (SB) in comparison with mpMRI of the prostate.

METHODS AND RESULTS

Three hundred and eight men who underwent mpMRI due to elevated PSA values between 2015 and 2020 were studied at university hospital Aachen, Germany. MRI-images were divided into cohorts with suspicious findings (PI-RADS ≥ 3) and negative findings (PI-RADS < 3). In patients with PI-RADS ≥ 3 TB combined with SB was performed. A part of this group underwent RP subsequently. In patients with PI-RADS < 3 and clinical suspicion SB was performed. In the PI-RADS ≥ 3 group (n = 197), TB combined with SB was performed in 194 cases. Three cases were lost to follow-up. Biopsy yielded 143 positive biopsies and 51 cases without carcinoma. TB detected 71% (102/143) and SB 98% (140/143) of the overall 143 carcinoma. Overall, 102 carcinomas were detected by TB, hereof 66% (67/102) clinically significant (Gleason ≥ 3+4) and 34% (35/102) clinically insignificant carcinoma (Gleason 3+3). SB detected 140 carcinomas, hereof 64% (90/140) csPCA and 36% (50/140) nsPCA. Forty-one of the overall 143 detected carcinoma were only found by SB, hereof 46% (19/41) csPCA and 54% (22/41) nsPCA. Tumor locations overlapped in 44% (63/143) between TB and SB. In 25% (36/143), SB detected additional tumor foci outside the target lesions. 70/143 patients subsequently underwent RP. The detection of tumor foci was congruent between mpMRI and prostatectomy specimen in 79% (55/70) of cases. Tumor foci were mpMRI occult in 21% (15/70) of cases. In the group with negative mpMRI (n = 111), biopsy was performed in 81 cases. Gleason ≥ 3+4 carcinoma was detected in 7% and Gleason 3+3 in 24% cases.

CONCLUSION

There was a notable number of cases in which SB detected tumor foci that were mpMRI occult and could have been missed by TB alone. Therefore, additional systematic random biopsy is still required. A supplemental random biopsy should be considered depending on the overall clinical suspicion in negative mpMRI.

circPVT1 Inhibits the Proliferation and Aids in Prediction of the Prognosis of Bladder Cancer

Background

Circular RNA PVT1 (circPVT1) is aberrantly expressed in several cancers, but its functional role and clinical relevance in bladder urothelial carcinoma (BLCA) remain unknown. This study aimed to identify the expression level of circPVT1 in BLCA and investigated its functional relevance with BLCA progression both in vitro and in vivo.

Methods

GEPIA, UALCAN, and OncoLnc were referred to presented data. Quantitative real-time PCR (qPCR) was used for the measurement of transnational expression of genes in BLCA specimens and cell lines. Immunohistochemistry (IHC) and fluorescence in situ hybridization analysis (FISH) assays were performed to detect HER2 amplification, Pearson's correlation analysis to analyze the correlation between circPVT1 expression and clinical characteristics, Cox regression and K-M survival analyses to analyze prognostic factors. A nomogram was constructed for predicting prognosis. The proliferation of cells was measured by CCK-8 and colony formation assay, and the proliferation in vivo was evaluated using nude mouse models. qPCR was used to detect the expression of proliferation-related genes.

Results

circPVT1 was but mRNA PVT1 was not significantly overexpressed in BLCA. A high circPVT1 expression was associated with a better survival and negative HER2, but not with age, gender, and T stage. circPVT1 was an independent prognostic factor for the overall survival of BLCA patients. Knocking down circPVT1 promoted BLCA proliferation in vitro and in vivo. Knocking down circPVT1 upregulated ERBB2, MKI67, and PCNA expression and downregulated TP53 expression, but exerted no influence on CCND1 and CCNB1 expression.

Conclusion

circPVT1 is a tumor suppressor and novel prognostic biomarker for BLCA.

International Society of Urological Pathology (ISUP) Consensus Conference on Current Issues in Bladder Cancer. Working Group 2: Grading of Mixed Grade, Invasive Urothelial Carcinoma Including Histologic Subtypes and Divergent Differentiations, and Non-Urothelial Carcinomas

The 2022 International Society of Urological Pathology (ISUP) Consensus Conference on Urinary Bladder Cancer Working Group 2 was tasked to provide evidence-based proposals on the applications of grading in noninvasive urothelial carcinoma with mixed grades, invasive urothelial carcinoma including subtypes (variants) and divergent differentiations, and in pure non-urothelial carcinomas. Studies suggested that predominantly low-grade noninvasive papillary urothelial carcinoma with focal high-grade component has intermediate outcome between low- and high-grade tumors. However, no consensus was reached on how to define a focal high-grade component. By 2004 WHO grading, the vast majority of lamina propria-invasive (T1) urothelial carcinomas are high-grade, and the rare invasive low-grade tumors show only limited superficial invasion. While by 1973 WHO grading, the vast majority of T1 urothelial carcinomas are G2 and G3 and show significant differences in outcome based on tumor grade. No consensus was reached if T1 tumors should be graded either by the 2004 WHO system or by the 1973 WHO system. Because of the concern for underdiagnosis and underreporting with potential undertreatment, participants unanimously recommended that the presence of urothelial carcinoma subtypes and divergent differentiations should be reported. There was consensus that the extent of these subtypes and divergent differentiations should also be documented in biopsy, transurethral resection, and cystectomy specimens. Any distinct subtype and divergent differentiation should be diagnosed without a threshold cutoff, and each type should be enumerated in tumors with combined morphologies. The participants agreed that all subtypes and divergent differentiations should be considered high-grade according to the 2004 WHO grading system. However, participants strongly acknowledged that subtypes and divergent differentiations should not be considered as a homogenous group in terms of behavior. Thus, future studies should focus on individual subtypes and divergent differentiations rather than lumping these different entities into a single clinicopathological group. Likewise, clinical recommendations should pay attention to the potential heterogeneity of subtypes and divergent differentiations in terms of behavior and response to therapy. There was consensus that invasive pure squamous cell carcinoma and pure adenocarcinoma of the bladder should be graded according to the degree of differentiation. In conclusion, this summary of the International Society of Urological Pathology Working Group 2 proceedings addresses some of the issues on grading beyond its traditional application, including for papillary urothelial carcinomas with mixed grades and with invasive components. Reporting of subtypes and divergent differentiation is also addressed in detail, acknowledging their role in risk stratification. This report could serve as a guide for best practices and may advise future research and proposals on the prognostication of these tumors.

Comparing trimodal therapy with radical cystectomy in muscle-invasive bladder cancer: an updated meta-analysis

Background

We conducted this meta-analysis to compare the two muscle-invasive bladder cancer (MIBC) treatment modalities in terms of cancer-specific survival (CSS) and other outcome indicators.

Method

A systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews (PRISMA) guidelines. The search was conducted using various academic databases including Scopus, PubMed, Cochrane database, EMBASE, Chinese biomedical literature database, Wan fang databases, and China National Knowledge Internet databases between 1966 and December 2023. This review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO) No. (CRD42023398977).

Result

This study included a total of 54,816 patients diagnosed with bladder cancer from 14 studies, of which 6,228 patients were assigned to the trimodal therapy (TMT) group and 48,588 patients were assigned to the radical cystectomy (RC) group. Based on the results, the RC group exhibited a higher rate of survival than the TMT group [pooled hazard ratio (HR) = 1.23, 95% CI: 1.18-1.28, Z = 1.46, P < 0.001]. In terms of CSS, patients in the RC group had a longer CSS compared with those in the TMT group (pooled HR = 1.47, 95% CI: 1.29-1.67, Z = 5.893, P < 0.001). Compared with RC, TMT is significantly associated with an increased risk of both types of mortality (pooled HR: 1.30, P < 0.001).

Conclusion

Overall, the findings of this meta-analysis suggest that RC treatment may be associated with improved overall survival. Moreover, it was observed that cancer-specific survival was significantly prolonged among patients in the RC group as opposed to those who received TMT. In addition, it was shown that patients who received TMT exhibited a higher risk of all-cause mortality when compared with those who underwent RC.

Fluorescence Confocal Microscopy in Urological Malignancies: Current Applications and Future Perspectives

Fluorescence confocal microscopy (FCM) represents a novel diagnostic technique able to provide real-time histological images from non-fixed specimens. As a consequence of its recent developments, FCM is gaining growing popularity in urological practice. Nevertheless, evidence is still sparse, and, at the moment, its applications are heterogeneous. We performed a narrative review of the current literature on this topic. Papers were selected from the Pubmed, Embase, and Medline archives. We focused on FCM applications in prostate cancer (PCa), urothelial carcinoma (UC), and renal cell carcinoma (RCC). Articles investigating both office and intraoperative settings were included. The review of the literature showed that FCM displays promising accuracy as compared to conventional histopathology. These results represent significant steps along the path of FCM's formal validation as an innovative ready-to-use diagnostic support in urological practice. Instant access to a reliable histological evaluation may indeed significantly influence physicians' decision-making process. In this regard, FCM addresses this still unmet clinical need and introduces intriguing perspectives into future diagnostic pathways. Further studies are required to thoroughly assess the whole potential of this technique.

Development and validation of a preoperative nomogram to predict lymph node metastasis in patients with bladder urothelial carcinoma

PURPOSE

Predicting lymph node metastasis (LNM) in patients with bladder urothelial carcinoma (BUC) before radical cystectomy aids clinical decision making. Here, we aimed to develop and validate a nomogram to preoperatively predict LNM in BUC patients.

METHODS

Patients with histologically confirmed BUC, who underwent radical cystectomy and bilateral lymphadenectomy, were retrospectively recruited from two institutions. Patients from one institution were enrolled in the primary cohort, while those from the other were enrolled in the external validation cohort. Patient demographic, pathological (using transurethral resection of the bladder tumor specimens), imaging, and laboratory data were recorded. Univariate and multivariate logistic regression analyses were performed to explore the independent preoperative risk factors and develop the nomogram. Internal and external validation was conducted to assess nomogram performance.

RESULTS

522 and 215 BUC patients were enrolled in the primary and external validation cohorts, respectively. We identified tumor grade, infiltration, extravesical invasion, LNM on imaging, tumor size, and serum creatinine levels as independent preoperative risk factors, which were subsequently used to develop the nomogram. The nomogram showed a good predictive accuracy, with area under the receiver operator characteristic curve values of 0.817 and 0.825 for the primary and external validation cohorts, respectively. The corrected C-indexes, calibration curves (after 1000 bootstrap resampling), decision curve analysis results, and clinical impact curves demonstrated that the nomogram performed well in both cohorts and was highly clinically applicable.

CONCLUSION

We developed a nomogram to preoperatively predict LNM in BUC, which was highly accurate, reliable, and clinically applicable.

A Validation Study of cT-Categories in the Swedish National Urinary Bladder Cancer Register-Norrland University Hospital

BACKGROUND

In Sweden, all patients with urinary bladder cancer (UBC) are recorded in the Swedish National Register for Urinary Bladder Cancer (SNRUBC). The purpose of this study was to validate the registered clinical tumour categories (cT-categories) in the SNRUBC for Norrland University Hospital, Sweden, from 2009 to 2020, inclusive.

METHODS

The medical records of all 295 patients who underwent radical cystectomy for the treatment of UBC were reviewed retrospectively. Possible factors impacting the cT-categories were identified. To optimise cT-classification, computed tomography urography of all patients with suspected tumour-associated hydronephrosis (TAH) or suspected tumour in bladder diverticulum (TIBD) were retrospectively reviewed by a radiologist. Discrepancy was tested with a logistic regression model.

RESULTS

cT-categories differed in 87 cases (29.5%). Adjusted logistic regression analysis found TIBD and TAH as significant predictors for incorrect registration; OR = 7.71 (p < 0.001), and OR = 17.7, (p < 0.001), respectively. In total, 48 patients (68.6%) with TAH and 12 patients (52.2%) with TIBD showed discrepancy regarding the cT-category. Incorrect registration was mostly observed during the years 2009-2012.

CONCLUSION

The study revealed substantial incorrect registration of cT-categories in SNRUBC. A major part of the misclassifications was related to TAH and TIBD. Registration of these variables in the SNRUBC might be considered to improve correct cT-classification.

Use of machine learning to predict bladder cancer survival outcomes: a systematic literature review

INTRODUCTION

The objective of this systematic review is to summarize the use of machine learning (ML) in predicting overall survival (OS) in patients with bladder cancer.

METHODS

Search terms for bladder cancer, ML algorithms, and mortality were used to identify studies in PubMed and Web of Science as of February 2022. Notable inclusion/exclusion criteria contained the inclusion of studies that utilized patient-level datasets and exclusion of primary gene expression-related dataset studies. Study quality and bias were assessed using the International Journal of Medical Informatics (IJMEDI) checklist.

RESULTS

Of the 14 included studies, the most common algorithms were artificial neural networks (n = 8) and logistic regression (n = 4). Nine articles described missing data handling, with five articles removing patients with missing data entirely. With respect to feature selection, the most common sociodemographic variables were age (n = 9), gender (n = 9), and smoking status (n = 3), with clinical variables most commonly including tumor stage (n = 8), grade (n = 7), and lymph node involvement (n = 6). Most studies (n = 10) were of medium IJMEDI quality, with common areas of improvement being the descriptions of data preparation and deployment.

CONCLUSIONS

ML holds promise for optimizing bladder cancer care through accurate OS predictions, but challenges related to data processing, feature selection, and data source quality must be resolved to develop robust models. While this review is limited by its inability to compare models across studies, this systematic review will inform decision-making by various stakeholders to improve understanding of ML-based OS prediction in bladder cancer and foster interpretability of future models.

Uncovering the Secrets of Prostate Cancer's Radiotherapy Resistance: Advances in Mechanism Research

Prostate cancer (PCa) is a critical global public health issue with its incidence on the rise. Radiation therapy holds a primary role in PCa treatment; however, radiation resistance has become increasingly challenging as we uncover more about PCa's pathogenesis. Our review aims to investigate the multifaceted mechanisms underlying radiation therapy resistance in PCa. Specifically, we will examine how various factors, such as cell cycle regulation, DNA damage repair, hypoxic conditions, oxidative stress, testosterone levels, epithelial-mesenchymal transition, and tumor stem cells, contribute to radiation therapy resistance. By exploring these mechanisms, we hope to offer new insights and directions towards overcoming the challenges of radiation therapy resistance in PCa. This can also provide a theoretical basis for the clinical application of novel ultra-high-dose-rate (FLASH) radiotherapy in the era of PCa.

Hyperthermia intravesical chemotherapy acts as a promising alternative to bacillus Calmette-Guérin instillation in non-muscle-invasive bladder cancer: a network meta-analysis

Introduction

With the shortage of bacillus Calmette-Guérin (BCG) vaccine, it is important to find an alternative to BCG instillation, which is the most commonly used adjuvant treatment for non-muscle-invasive bladder cancer (NMIBC) patients after transurethral resection of bladder tumor treatment (TURBt) to delay tumor recurrence. Hyperthermia intravesical chemotherapy (HIVEC) with mitomycin C (MMC) is a potential treatment choice. We aim to compare HIVEC with BCG instillation for the preventive efficacy of bladder tumor recurrence and progression.

Methods

A network meta-analysis (NMA) was taken with MMC instillation and TURBt as the attached comparators. Randomized controlled trials (RCTs) with NIMBC patients after TURBt were included. Articles with pure BCG unresponsive patients and combined therapies were excluded. The study protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO, CRD42023390363).

Results

It was found that HIVEC had a non-significant 22% relative reduction in bladder tumor recurrence compared with BCG instillation [HIVEC vs. BCG: HR 0.78, 95% credible interval (CrI) 0.55-1.08] and a nonsignificant higher risk of bladder tumor progression (BCG vs. HIVEC: HR 0.77, 95% CrI 0.22-3.03).

Discussion

HIVEC is a potential alternative to BCG, and it is expected to be the standard therapy for NMIBC patients after TURBt during the global shortage of BCG.

Systematic Review Registration

PROSPERO identifier, CRD42023390363.

T1G1 Bladder Cancer: Prognosis for this Rare Pathological Diagnosis Within the Non-muscle-invasive Bladder Cancer Spectrum

BACKGROUND

The pathological existence and clinical consequence of stage T1 grade 1 (T1G1) bladder cancer are the subject of debate. Even though the diagnosis of T1G1 is controversial, several reports have consistently found a prevalence of 2-6% G1 in their T1 series. However, it remains unclear if T1G1 carcinomas have added value as a separate category to predict prognosis within the non-muscle-invasive bladder cancer (NMIBC) spectrum.

OBJECTIVE

To evaluate the prognostic value of T1G1 carcinomas compared to TaG1 and T1G2 carcinomas within the NMIBC spectrum.

DESIGN, SETTING, AND PARTICIPANTS

Individual patient data for 5170 primary Ta and T1 bladder tumors from 17 hospitals in Europe and Canada were analyzed. Transurethral resection (TUR) was performed between 1990 and 2018.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Time to recurrence and progression were analyzed using cumulative incidence functions, log-rank tests, and multivariable Cox regression models stratified by institution.

RESULTS AND LIMITATIONS

T1G1 represented 1.9% (99/5170) of all carcinomas and 5.3% (99/1859) of T1 carcinomas. According to primary TUR dates, the proportion of T1G1 varied between 0.9% and 3.5% per year, with similar percentages in the early and later calendar years. We found no difference in time to recurrence between T1G1 and TaG1 (p = 0.91) or between T1G1 and T1G2 (p = 0.30). Time to progression significantly differed between TaG1 and T1G1 (p < 0.001) but not between T1G1 and T1G2 (p = 0.30). Multivariable analyses for recurrence and progression showed similar results.

CONCLUSIONS

The relative prevalence of T1G1 diagnosis was low and remained constant over the past three decades. Time to recurrence of T1G1 NMIBC was comparable to that for other stage/grade NMIBC combinations. Time to progression of T1G1 NMIBC was comparable to that for T1G2 but not for TaG1, suggesting that treatment and surveillance of T1G1 carcinomas should be more like the approaches for T1G2 NMIBC in accordance with the intermediate and/or high risk categories of the European Association of Urology NMIBC guidelines.

PATIENT SUMMARY

Although rare, stage T1 grade 1 (T1G1) bladder cancer is still diagnosed in daily clinical practice. Using individual patient data from 17 centers in Europe and Canada, we found that time to progression of T1G1 cancer was comparable to that for T1G2 but not TaG1 cancer. Therefore, our results suggest that primary T1G1 bladder cancers should be managed with more aggressive treatment and more frequent follow-up than for low-risk bladder cancer.

Micropapillary bladder cancer: an evolving biology

PURPOSE OF REVIEW

To summarize a comprehensive overview of more recent evidence on micropapillary bladder cancer (MPBC), focusing on actual incidence, clinical features, therapeutic strategies, and prognosis.

RECENT FINDINGS

MPBC generally exhibits an aggressive behaviour compared with pure urothelial carcinoma (pUC) with advances in tumour stage and nodal and distant spread at diagnosis. Due to its rarity and presence of only small sample size and retrospective studies, no consensus currently exists regarding the most effective therapeutic strategy to be performed among nonmuscle-invasive (conservative treatment versus immediate radical cystectomy) and muscle-invasive MPBC (neoadjuvant therapy versus upfront radical cystectomy versus adjuvant chemotherapy).

SUMMARY

The incidence of MPBC is recently increased according to latter literature, ranging from 2.9 to 7.6% of all bladder cancer. Despite its aggressive behaviour at time of presentation, more recent evidence fails to demonstrate a significant association between MPBC and worse outcomes compared with pUC when adjusted for clinical and pathological features. According to latter evidence, MPBC pathological response to NAC appears to be unsatisfactory compared with pUC patients while neoadjuvant immunotherapy with Pembrolizumab may represent an effective treatment among MPBC patients, based on PD-L1 and TMB expression.