Micropapillary Urothelial Carcinoma of the Bladder: A Systematic Review and Meta-analysis of Disease Characteristics and Treatment Outcomes

Early experience with sequential intravesical gemcitabine and docetaxel for micropapillary variant non-muscle invasive bladder cancer

BACKGROUND

Guidelines lack clear recommendations regarding conservative management of micropapillary (MP) variant non-muscle invasive bladder cancer (NMIBC). Bladder-sparing therapy using intravesical Bacillus Calmette-Guerin (BCG) has been reported although there are concerns regarding recurrence and progression with this approach. Due to the ongoing BCG shortage, we have utilized sequential intravesical gemcitabine and docetaxel (Gem/Doce) as primary therapy for NMIBC, including some cases with limited MP urothelial carcinoma (MPUC). To compare oncologic outcomes of patients with non-muscle invasive MPUC and conventional UC treated with Gem/Doce.

METHODS

A secondary analysis of 138 patients with high-risk NMIBC treated with intravesical Gem/Doce from January 2011 to December 2021 was performed. Oncologic outcomes were compared in patients with or without MPUC using the Kaplan-Meier method.

RESULTS

Median follow-up (f/u) for all patients was 23 months (IQR 13-34). There were 129 patients with pure UC and 9 with MPUC. In those with MPUC, all were high-grade (HG), 8/9 were stage T1, 7/9 had a focal MP component (extent < 10%), 3/9 had concomitant CIS, and 2/9 had lymphovascular invasion. All MPUC tumors were re-resected, and 4 had T0, 3 had T1 HG, 1 had Ta HG, 1 had carcinoma in situ (CIS); none had residual MP or LVI tumors before Gem/Doce treatment. The 24-month high-grade recurrence-free survival was 89% and 80% in patients with MPUC and pure UC, respectively. Survival outcomes did not significantly differ between patients with and without MPUC. Four patients with MPUC experienced recurrent NMIBC after Gem/Doce, and all were treated successfully with rescue sequential intravesical valrubicin and docetaxel (Val/Doce). Pathology of these four recurrent patients revealed more aggressive histologic features in the original tumor including: multifocal tumor (3/4), T1 HG disease (4/4), concomitant CIS (2/4), and moderate MP variant extent (30%) (1/4). No patient with MPUC underwent cystectomy, experienced progression, or died at last follow-up (median f/u of 43 months).

CONCLUSIONS

Gem/Doce with Val/Doce rescue appears to have activity against carefully selected non-muscle invasive MPUC with favorable histology. Larger prospective trials are needed to validate these results.

Prognostic value of micrometric substaging in pT1 bladder cancer patients treated with en-bloc transurethral resection

AIMS

We aimed to assess the oncological impact of micrometric extent of invasion in patients with pT1 bladder cancer (BCa) who underwent en-bloc resection for bladder tumour (ERBT).

METHODS AND RESULTS

We retrospectively analysed the records and specimens of 106 pT1 high-grade BCa patients who underwent ERBT. The extent of invasion, such as depth from basal membrane, number of invasive foci, maximum width of invasive focus, muscularis mucosae invasion and infiltration pattern (pattern A: solid sheet-like, nodular or nested growth, pattern B: trabecular, small cluster or single-cell pattern) were evaluated by a single genitourinary pathologist. The end-points were recurrence-free (RFS) and progression-free survival (PFS). Within a median follow-up of 23 months, overall, 36 patients experienced recurrence and 13 patients experienced disease progression. The 2-year PFS differed significantly depending on depth from basal membrane (< 1.3 mm: 94.8% versus ≧ 1.3 mm: 65.2%, P = 0.005), maximum width of invasive focus (< 4 mm: 91.7% versus ≧ 4 mm: 62.3%, P < 0.001), muscularis mucosae (MM) invasion (above MM = 96.1% versus into or beyond MM = 64.8%, P = 0.002) and infiltration pattern (pattern A: 100% versus pattern B: 83.3%, P = 0.037). In a multivariable analysis, MM invasion [hazard ratio (HR) = 4.54, 95% confidence interval (CI) = 1.25-16.5] and maximum width of invasive focus ≧ 4 mm (HR = 4.79, 95% CI = 1.25-16.5) were independent prognostic factors of progression.

CONCLUSIONS

En-bloc resection facilitates the evaluation of pathologic variables that might be useful in predicting disease recurrence and progression. In particular, not only the MM invasion but also the maximum width of invasion focus, reflecting the invasive volume, appear to be reliable prognosticators for disease progression.

Effectiveness of Adjuvant Chemotherapy in Variant Histology Upper Tract Urothelial Carcinoma Following Radical Nephroureterectomy: Stabilized Inverse Probability Treatment Weighting Analysis of Single Center Experience

PURPOSE

The study aimed to investigate the impact of adjuvant chemotherapy on time to recurrence (TTR) and overall survival (OS) in patients with histologic variants of upper tract urothelial carcinoma (VUTUC) following radical nephroureterectomy (RNU).

MATERIALS AND METHODS

A retrospective review of 131 VUTUC patients' medical records, from a pool of 368 non-metastatic localized or locally advanced UTUC cases, treated at a single tertiary referral center between January 2011 and January 2021. The intervention was adjuvant chemotherapy administration post-RNU. TTR and OS were evaluated using Kaplan-Meier and Cox proportional hazard regression, covariates adjusted for age, postoperative GFR, history of neoadjuvant chemotherapy, T and N stage with stabilized inverse probability of treatment weighting (sIPTW).

RESULTS

The application of adjuvant chemotherapy showed a significant extension in TTR (P = .01), but no substantial impact on OS (P = .19) after sIPTW adjustment for covariates. Multivariate analysis revealed adjuvant chemotherapy, tumor size, and lymphovascular invasion as significant prognostic factors for TTR. In contrast, only tumor size and perineural invasion were significant for OS. Adjuvant chemotherapy reduced the progression risk in certain VUTUC subtypes (squamous or glandular/micropapillary), but not in sarcomatoid variants.

CONCLUSIONS

Adjuvant chemotherapy appears to improve TTR, albeit without a significant effect on OS, in nonmetastatic localized and locally advanced VUTUC patients post-RNU. While beneficial to some VUTUC subtypes, it did not yield significant advantages for sarcomatoid variants. Despite adjustments for known confounders, the study's findings may be subject to potential selection bias and unmeasured confounding factors.

Efficiency of bladder-sparing strategies for bladder cancer: an umbrella review

Bladder preservation (BP) has emerged as a clinical alternative to radical cystectomy (RC) for alleviating the substantial physical and psychological burden imposed on localized bladder cancer patients. Nevertheless, disparities persist in the comparative evaluations of BP and RC. We aimed to address the disparities between BP and RC. An umbrella review and meta-analysis were conducted to explore these disparities. We extracted data from meta-analyses and randomized controlled trials (RCTs) selected after searching PubMed, Embase, Web of Science, and the Cochrane Database of Systematic Reviews. Review Manager 5.4.0 and R x64 4.1.3 were used to evaluate the collected data. Our study included 11 meta-analyses and 3 RCTs. In terms of progression-free survival, all the meta-analyses reported that patients with localized bladder cancer who underwent BP exhibited outcomes comparable to those who underwent RC. Meta-analyses regarding the outcomes of cancer-specific survival (CSS) and overall survival (OS) are controversial. To solve these issues, we conducted a pooled analysis of CSS data, which supported the similarity of CSS between BP and RC with no significant heterogeneity [odds ratio (OR): 1.2; 95% confidence interval (CI): 0.71-2.02; I2 = 26%]. Similarly, the pooled OS results extracted from three RCTs indicated the comparability of OS between BP and RC with no significant heterogeneity (OR: 1.12; 95% CI: 0.41-3.07; I2 = 33%). A combination of umbrella review and meta-analysis results suggested that BP had survival rates comparable to those of RC. We suggest that BP may be a more eligible therapy than RC for patients with localized muscle-invasive bladder cancer. This conclusion warrants further validation through randomized controlled trials.

Does Bladder Cancer Subtype Influence Pathologic Complete Response (pCR) and Pelvic Diffusion-Weighted Magnetic Resonance Imaging (DW-MRI) Response Evaluation After Neoadjuvant Chemotherapy? Pathological Perspective

INTRODUCTION

We aimed to provide a pathological perspective on the management of muscle-invasive bladder cancer (MIBC) by correlating the prechemotherapy transurethral resection of bladder tumor findings and postchemotherapy radiologic evaluation with final radical cystectomy (RC) findings.

MATERIALS AND METHODS

This retrospective study included 79 MIBC patients treated with neoadjuvant chemotherapy (NAC) and RC. Pelvic diffusion-weighted magnetic resonance imaging (DW-MRI) and pathologic reports were retrieved from our institutional database. All pathology slides were reviewed based on diagnostic criteria with high interobserver reproducibility.

RESULTS

Pathologic complete response (pCR) was confirmed in 32 patients (40.5%). The concordance and discordance between MRI and RC findings occurred in 68.3% and 31.7% of cases, respectively. The 21.5% of cases that were clinical CR (cCR) on MRI actually achieved pCR on RC specimens and 46.8% of cases that were non-cCR on MRI were actually non-pCR on RC specimens. In 19.0% of cases, RC findings were pCR, but MRI demonstrated residual tumor and the opposite was 12.7%. The greatest discrepancy between the 2 methods (75%, 3/4) was for the plasmacytoid subtype. Plasmacytoid histology was the most common histological subtype identified in RC specimens after NAC, followed by micropapillary and squamous histologies.

CONCLUSIONS

We found that all cases with plasmacytoid and micropapillary subtypes, and squamous differentiation did not show pCR. In particular, the largest discrepancy between MRI findings and RC pathology after NAC was seen in the plasmacytoid subtype. An accurate pathologic diagnosis based on strict criteria to identify histological subtypes of MIBC is necessary for proper treatment.

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.

Predictors of response to neoadjuvant therapy in urothelial cancer

Neoadjuvant cisplatin-based chemotherapy (NACC) followed by radical cystectomy is the standard treatment for localized muscle-invasive bladder cancer (MIBC). Patients who achieve a complete pathological response following NACC have better overall survival than those with residual disease. However, a subset of patients does not derive benefit from NACC while experiencing chemotherapy-related side effects that may delay cystectomy, which can be detrimental. There is a need for predictive and prognostic biomarkers to better stratify patients who will derive benefits from NACC. This review summarizes the currently available literature on various predictors of response to neoadjuvant chemotherapy. Covered predictors include clinical factors, treatment regimens (including chemotherapy and immunotherapy), histological predictors, and molecular predictors such as DNA repair genes, p53, FGFR3, ERBB2, Bcl-2, EMMPRIN, survivin, choline-phosphate cytidylyltransferase-α, epigenetic markers, immunological markers, other molecular predictors and gene expression profiling. Further, we elaborate on the potential role of neoadjuvant immunotherapy and the correlative biomarkers of response.

Proposal for a Novel Histological Scoring System as a Potential Grading Approach for Muscle-invasive Urothelial Bladder Cancer Correlating with Disease Aggressiveness and Patient Outcomes

BACKGROUND

Grading of muscle-invasive bladder cancer (MIBC) according to the current World Health Organization (WHO) criteria is controversial due to its limited prognostic value. All MIBC cases except a tiny minority are of high grade.

OBJECTIVE

To develop a prognostic histological scoring system for MIBC integrating histomorphological phenotype, stromal tumor-infiltrating lymphocytes (sTILs), tumor budding, and growth and spreading patterns.

DESIGN, SETTING, AND PARTICIPANTS

Tissue specimens and clinical data of 484 patients receiving cystectomy and lymphadenectomy with curative intent with or without adjuvant chemotherapy. Histomorphological phenotypes, sTILs, tumor budding, and growth and spreading patterns were evaluated and categorized into four grade groups (GGs). GGs were correlated with molecular subtypes, immune infiltration, immune checkpoint expression, extracellular matrix (ECM) remodeling, and epithelial-mesenchymal transition (EMT) activity.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

GGs were associated with overall (OS), disease-specific (DSS), and progression-free (PFS) survival in univariable and multivariable analyses. Association with biological features was analyzed with descriptive statistics.

RESULTS AND LIMITATIONS

Integration of two histomorphological tumor groups, three sTILs groups, three tumor budding groups, and four growth/spread patterns yielded four novel GGs that had high significance in the univariable survival analysis (OS, DSS, and PFS). GGs were confirmed as independent prognostic predictors with the greatest effect in the multivariable Cox regression analysis. Correlation with molecular data showed a gradual transition from basal to luminal subtypes from GG1 to GG4; a gradual decrease in survival, immune infiltration, and immune checkpoint activity; and a gradual increase in ECM remodeling and EMT activity.

CONCLUSIONS

We propose a novel, prognostically relevant, and biologically based scoring system for MIBC in cystectomies applicable to routine pathological sections.

PATIENT SUMMARY

We developed a novel approach to assess the aggressiveness of advanced bladder cancer, which allows improved risk stratification compared with the method currently proposed by the World Health Organization.

Neoadjuvant Chemotherapy Prior to Radical Cystectomy for Muscle-Invasive Bladder Cancer With Variant Histology: A Systematic Review and Meta-Analysis of Survival Outcomes and Pathological Features

PURPOSE

To conduct systematic review and meta-analysis to evaluate effects of neoadjuvant chemotherapy (NAC) on survival and histopathological outcomes of variant histology (VH) of urothelial carcinoma (UC) of bladder.

METHODS

This systematic review was registered in PROSPERO (CRD42023389115). Literature search was conducted in PubMed/Medline, Embase, and Cochrane Library for studies published up to January 2023. Population, intervention, comparator, outcome, and study design were as follows: bladder cancer patients with VH (population), neoadjuvant chemotherapy (intervention), radical cystectomy only (comparators), oncological survival and pathologic response (outcomes), and retrospective or prospective (study design).

RESULTS

Finally, a total of 17 studies were included in the present study (quantitative analysis, n = 17; qualitative analysis, n = 12). Pooled HR was 0.49 (95% CI: 0.31-0.76; P = .002) for OS. Pooled HR was 0.61 (95% CI: 0.38-0.98; P = .04) for CSS. Pooled HR was 0.44 (95% CI: 0.21-0.93; P = .03) in PFS. Pooled OR was 6.61 (95% CI: 4.50-9.73; P < .00001) in complete pathologic response. Pooled OR was 9.59 (95% CI: 3.56-25.85; P < .00001) in any pathologic response. Evidence quality assessments for each 5 comparisons using the GRADE approach were that Certainty was moderate in 1, low in 1, and very low in 3.

CONCLUSIONS

Administration of NAC before surgery in bladder cancer patients with VH might confer better survival outcomes and higher pathologic down staging rate than no administration of NAC before surgery.

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.

The perioperative and long-term outcomes of patients with variant histology bladder cancer undergoing radical cystectomy: A propensity score-matched analysis with pure urothelial carcinoma

OBJECTIVES

To assess the perioperative and long-term outcomes after open radical cystectomy in patients with histological variants versus pure urothelial carcinoma.

METHODS

Patients with a variant histology carcinoma of the urinary bladder were matched through a propensity score analysis with those with pure urothelial carcinoma on a 1:3 ratio. The two groups were compared in terms of perioperative and long-term morbidity and mortality.

RESULTS

Overall, 148 individuals were included in the present retrospective study (37 with variant histology and 111 with pure urothelial carcinoma). A total of 107 (72.3%) individuals presented at least one perioperative complication based on the Clavien-Dindo classification. This proportion was similar between patients with urothelial versus variant histology carcinoma (P = .22). In the long term, the number of patients with clinically significant incisional hernia requiring surgery [14 (12.7%) vs 3 (8.3%), P = .68], uretero-intestinal/uretero-cutaneous strictures or any other complication related to the applied urinary diversion [15 (13.6%) vs 7 (19.4%), P = .56], as well as the number of patients presenting with septicemia [17 (15.5%) vs 10 (27.8%), P = .16] or with urinary tract obstruction [12 (10.9%) vs 4 (11.1%), P > .99] at follow-up did not differ between urothelial versus variant histology carcinoma. The survival analysis with Kaplan-Meier curves and the univariate Cox regression model suggested that the risk of death from any cause was increased in patients with variant compared to pure urothelial histology (log-rank test = 0.045, hazard ratio: 1.7, 95% confidence interval: 1.01-2.87, P = .047).

CONCLUSIONS

Perioperative morbidity and mortality are comparable in patients with variant histology versus pure urothelial carcinoma.

Perioperative systemic therapy in muscle invasive bladder cancer: Current standard method, biomarkers and emerging strategies

Bladder cancer ranks as the 10th most common cancer type globally, and muscle-invasive disease accounts for approximately 25% of newly diagnosed bladder cancers. Despite definitive treatment, 50% of patients with muscle-invasive bladder cancer (MIBC) develop metastasis within 2 years, leading to death. Perioperative systemic therapy is generally recommended to control local relapse or distant metastasis after surgical resection for patients with MIBC. Cisplatin-based neoadjuvant chemotherapy followed by radical cystectomy is the current standard treatment to improve oncologic control and survival outcomes. Adjuvant chemotherapy is recommended for patients with pathological T3-4 or positive lymph nodes after radical cystectomy if no neoadjuvant chemotherapy was given. Nonetheless, perioperative systemic therapy is not applied widely because of its toxicity, and less than 25% of patients receive cisplatin-based neoadjuvant chemotherapy. Therefore, the development of predictive biomarkers for neoadjuvant chemotherapy efficacy and alternative effective regimens for cisplatin-ineligible patients are important. Furthermore, recently, novel anticancer agents such as immune checkpoint inhibitors and antibody-drug conjugates have proven survival benefits in the metastatic setting, thereby expanding their therapeutic applications to the perioperative setting for non-metastatic MIBC. Herein, we discuss the current status and future perspectives of perioperative systemic strategies for MIBC.

Clinicopathologic analysis of patients undergoing repeat transurethral resection of bladder tumour following an initial diagnosis of urothelial carcinoma with lamina propria invasion and variant/divergent histology

AIMS

A subset of patients with urothelial carcinoma (UCa) and lamina propria (LP) invasion in bladder biopsies/transurethral resections (TURs) are at significant risk for recurrence and have increased rates of progression to UCa with muscularis propria (MP) invasion. The clinicopathologic features of this patient population has not been well characterised in the Pathology literature.

METHODS

We performed a search through our urologic pathology files and expert consult cases of the senior author for bladder biopsies/TURs of UCa with LP invasion and variant/divergent histology from 2014 to 2020. Patients with a prior diagnosis of UCa with MP invasion or upper tract UCa were excluded. Clinicopathologic data were obtained.

RESULTS

Ninety-five patients with at least one biopsy/TUR of UCa with LP invasion and variant/divergent histology were identified. Mean patient age was 72 years (range: 46-92 years) with a male predominance 2.3:1. Initial variant/divergent histologies identified were: glandular (35.8%), squamous (23.2%), micropapillary (20%), clear cell/lipid rich (12.6%), diffuse/signet ring/plasmacytoid (10.5%), nested (9.5%), sarcomatoid (6.3%), poorly differentiated/anaplastic (4.2%), small cell (2.1%), lymphoepithelioma-like (2.1%), osteoclast-like giant cells (1.1%) and tumour giant cells (1.1%). Two or more variant histologies were identified in 18.9% of these cases. The rate of micropapillary UCa was significantly higher in multifocal tumours compared with unifocal tumours (37% vs 7.1%).

CONCLUSIONS

In our cohort of patients undergoing early repeat biopsy/TUR, 75% of patients had persistent UCa. Additionally, almost 25% of patients had a prior diagnosis of UCa without a variant/divergent histology identified. Our findings highlight the critical role of repeat biopsy/TUR especially in a subset of patients who have variant/divergent histology, even in the absence of MP invasion.

Nomograms for predicting survival in patients with micropapillary bladder cancer: a real-world analysis based on the surveillance, epidemiology, and end results database and external validation in a tertiary center

BACKGROUND

The present study aimed to construct and validate nomograms that can be used to predict cancer-specific survival (CSS) and overall survival (OS) in patients with micropapillary bladder cancer.

METHODS

The data of 627 patients diagnosed with micropapillary bladder cancer between 2000 and 2018 were obtained from the surveillance, epidemiology, and end results database. Patients were randomly divided into the training and internal validation sets (7:3). The Cox proportional hazards regression model was applied to evaluate the association between variables and survival and then nomograms were constructed to predict the survival of an individual patient. The performance of nomograms was validated by using calibration curves, concordance index, receiver operating characteristic curves with the calculated area under the curve and decision curve analysis in the training and internal validation set. Data from 41 micropapillary bladder cancer patients at Qilu Hospital of Shandong University from 2000 to 2022 were collected for external validation.

RESULTS

Several independent risk factors were taken into the two nomograms (CSS and OS), including age, marital status, AJCC TMN stage, surgical approach, lymph node ratio, and tumor size while the OS nomogram additionally contained race. The concordance index of the training set, internal validation set, and external verification set were all over 0.7. The calibration curve indicated good consistence between the nomogram prediction and actual survival. Area under the curve and decision curve analysis results indicated great clinical usefulness of nomograms.

CONCLUSIONS

The nomograms predicting the survival outcome of patients with micropapillary bladder cancer would provide a valuable tool to help clinicians to evaluate the risk of patients and make individual treatment strategies.

Oncologic outcomes of neoadjuvant chemotherapy in patients with micropapillary variant urothelial carcinoma of the bladder

BACKGROUND

There is lack of consensus about the effectiveness of neoadjuvant platinum-based chemotherapy in patients with micropapillary variant urothelial carcinoma (MVUC) prior to radical cystectomy. We studied the association between neoadjuvant chemotherapy (NAC) and pathologic response (PR) among patients with micropapillary versus non-variant bladder urothelial carcinoma (UC).

METHODS

We queried the National Cancer Database to identify patients with localized UC and MVUC from 2004 to 2017. We restricted our analysis to patients who underwent radical cystectomy with or without NAC. We compared clinical, demographic, and pathologic characteristics associated with NAC. We used multivariable logistic regression and propensity score matching to examine the association between NAC and the occurrence of a pathologic complete response (pT0) and pathologic lymph node positivity (pN+). Kaplan Meier analyses and Cox proportional hazards models were used to assess overall survival (OS). We performed analyses among subsets of patients with clinical stage II (cT2) disease, as well as the entire cohort (cT2-T4).

RESULTS

We identified 18,761 patients, including 18,027 with non-variant UC and 734 patients with MVUC. Multivariable analysis revealed that NAC use was associated with greater odds of pT0 (9.64[7.62-12.82], P<0.001), and the association did not differ significantly between MVUC and non-variant UC. In a propensity matched analysis of patients with MVUC, NAC use was associated with higher odds of pT0 (OR 4.93 [2.43-13.18] P<0.001), lower odds of pN+ (OR 0.52 [0.26-0.92] P=0.047) and pathologic upstaging (OR 0.63 [0.34-0.97] P=0.042) in all stages. Similar findings were observed with cT2 disease. No significant association was seen between NAC and OS with MVUC (HR 0.89 [0.46-1.10] P=0.63), including the subset of patients with cT2 (HR 0.83 [0.49-1.06] P=0.58).

CONCLUSIONS

NAC is associated with similar pathologic and nodal responses in patients with localized MVUC and non-variant UC. Improvements in pathologic findings did not translate into OS in this retrospective hospital-based registry study.

Expression of autocrine motility factor receptor (AMFR) in human breast and lung invasive micropapillary carcinomas

The aim of this study was to evaluate the clinicopathological significance of autocrine motility factor receptor (AMFR) expression in a variety of human invasive micropapillary carcinomas (IMPC). AMFR expression was compared in 111 samples of a variety of human IMPCs which had intrinsic non-micropapillary components and with 26 cases of control pulmonary adenocarcinoma (CPA, carcinoma without an IMPC component) by immunohistochemistry (IHC). In the 137 cases analysed, AMFR expression was significantly elevated in the IMPC components compared to the non-IMPC components (p = .005) and normal tissues (p < .001). AMFR expression was also higher in the IMPC samples compared to their intrinsic non-IMPC components (p = .0234). Between the 69 cases of lung IMPC and 26 cases of CPA, AMFR expression was notably higher in the IMPC components than in the CPA components (p = .0455). However, there was no significant difference between the non-IMPC components in the lung and the CPA components (p = .4584). Moreover, in breast cancer, elevated AMFR expression was not significantly correlated with mixed type or pure type IMPC (p = .5969) or with age, gender, T stage, or lymph node metastasis (LNM). Between IMPC and CPA of the lung, there was no statistical significance in age, T stage, and LNM, where AMFR expression was higher in IMPC (p = .0071). Thus this study demonstrated that AMFR was overexpressed in a variety of human IMPC components compared with non-micropapillary components. This suggests that AMFR expression is a potential new prognostic indicator for different types of human IMPC, which might thus be a new therapeutic target.

Bladder Preservation for Muscle-Invasive Bladder Cancer With Variant Histology

A growing body of evidence has shown bladder-preservation with chemo-radiotherapy achieves comparable survival to Radical Cystectomy (5-year OS 50%-70%) and superior quality of life outcomes for patients with muscle-invasive urothelial carcinoma of the bladder (UC). However, up to 55% of patients harbor variant histology and in this review we aim to clarify the role of bladder-preservation for this group. We first draw the distinction between urothelial carcinoma with divergent differentiation (UCDD) and non-urothelial carcinoma (NUC). UCDD is common, increasing in prevalence, and whilst each subtype may have its own characteristics current evidence suggests comparable outcomes with radical cystectomy and bladder-preservation. Non-urothelial carcinoma is a collection of distinct pathologies each deserving of its own management strategy. However, these tumors are rare, and evidence is generated from retrospective studies with significant inherent bias. Small cell carcinoma of the bladder has good evidence for bladder-preservation; however, other pathologies such as Squamous Cell Carcinoma and Adenocarcinoma are not well supported. We recommend careful multidisciplinary appraisal of the evidence for each subtype and honest patient discussion about the limited evidence before reaching management decisions. As we look to the future molecular-profiling may help better characterize these tumors and aid in treatment selection.

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.

Neoadjuvant chemotherapy for muscle-invasive bladder cancer: does variant histology matter?

PURPOSE

The most frequent histology of bladder tumors is urothelial carcinoma. Most are pure urothelial carcinomas (PUC) but up to one-third of the cases present variant histological (VH) features. The aim of this study was to evaluate the role of variant histology in neoadjuvant chemotherapy (NAC) response in patients with urothelial muscle-invasive bladder cancer.

METHODS

We retrospectively analyzed data from 77 patients with bladder cancer who performed neoadjuvant chemotherapy at two institutions.

RESULTS

Complete pathological response (ypT0) was higher in patients with PUC (38.5%), comparing with VH (12%). Logistic regression analysis demonstrated that variant histology is associated with an 89% lesser likelihood of tumor downstaging, with advanced clinical T stages and positive smoking history as independent predictors. The estimated mean cancer-specific survival was 68.91 months for PUC patients and 50.23 months for VH patients (log rank test, P = 0.024). Multivariate Cox regression analysis demonstrated that VH and clinical T stage were independent predictors of cancer-specific survival, indicating a worse outcome for patients with VH and advanced clinical T stages.

CONCLUSIONS

There are only a few retrospective studies evaluating the clinical impact of variant histology tumors, which are mainly managed as PUC. Our results demonstrate that VH is associated with a worse likelihood of tumor downstaging after NAC and a worse cancer-specific survival in bladder cancer patients. There is a need for further studies and genetic analysis to identify the patients most likely to achieve ypT0 status and downstaging after NAC.

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.

Overview of histologic variants of urothelial carcinoma: current trends and narrative review on treatment outcomes

Background and Objective

The histologic variants of urothelial carcinoma (UC) are tumors arising from within the urothelium in which some component of the tumor morphology is other than urothelial. They are underdiagnosed, aggressive and have varying pathologic response rates to systemic chemotherapy. There are no consensus guidelines on the use of systemic chemotherapy in variant histology (VH) of UC. We performed a contemporary review on pathologic response rates to neoadjuvant systemic therapy and survival outcomes following radical cystectomy in order to provide a rationale for clinical practice recommendations on the management of UC with VH.

Methods

A PubMed literature search was conducted for all English articles from inception reporting either pathological response rates to neoadjuvant treatment or survival outcomes after radical cystectomy in non-metastatic VH of UC.

Key Content and Findings

Neoadjuvant chemotherapy (NAC) prior to radical cystectomy was shown to be a beneficial treatment strategy in UC with VH. The micropapillary, plasmacytoid, nested and sarcomatoid histologic variants were associated with worse survival outcomes compared to conventional UC and UC with squamous or glandular differentiation despite initial downstaging with chemotherapy. There is evidence of improved survival in patients with sarcomatoid differentiation receiving NAC compared to RC alone. The major prognostic factors that affect survival outcomes in VH of UC include histologic variant subtype, patient age, presence of lymphovascular invasion, hydronephrosis, nodal metastasis and advanced T stage at diagnosis. Recent studies demonstrate that VH of UC are heterogenous tumors and responsiveness to NAC may be a function of the molecular subtypes present.

Conclusions

Based on these findings, NAC to achieve pathologic downstaging prior to radical cystectomy is recommended for MIBC with VH. Biomarkers identified by molecular profiling with immunohistochemistry will need to be validated as predictors of response to NAC in future trials.

Prognostic Value of Platelet-to-Lymphocyte Ratio in Non-Muscle Invasive Bladder Cancer Patients: Intravesical Bacillus Calmette-Guerin Treatment After Transurethral Resection of Bladder Tumor

The objective of this study was to investigate the platelet-to-lymphocyte ratio (PLR) in patients who underwent intravesical treatment for non-muscle invasive bladder cancer (NMIBC). A total of 197 patients who underwent intravesical Bacillus Calmette-Guerin treatment after transurethral resection of bladder (TURB) were included. We divided the patients into different groups according to the treatment stage before and during induction treatment as Group 1 and Group 2, and set the change value of PLR as the Group 3. The cutoff values of PLR were determined through receiver operation characteristics curves analysis. we found a significant difference in recurrence-free survival (RFS) and progression-free survival (PFS) between patients with high serum PLR and those with low serum PLR in Group 1, as well as Group 2. Cox multivariate analysis revealed that tumor number ≥3, high grade, and history of carcinoma in situ (CIS) were significant factors predicting RFS and PFS. The PLR values before and during induction therapy could be used as predictors for the progression and recurrence of NMIBC patients receiving BCG immunotherapy. the PLR values after induction therapy have a stronger predictive power.

Non-muscle-invasive micropapillary bladder cancer has a distinct lncRNA profile associated with unfavorable prognosis

BACKGROUND

Molecular subtyping of bladder cancer has revealed luminal tumors generally have a more favourable prognosis. However, some aggressive forms of variant histology, including micropapillary, are often classified luminal. In previous work, we found long non-coding RNA (lncRNA) expression profiles could identify a subgroup of luminal bladder tumors with less aggressive biology and better outcomes.

OBJECTIVE

In the present study, we aimed to investigate whether lncRNA expression profiles could identify high-grade T1 micropapillary bladder cancer with differential outcome.

DESIGN, SETTING, AND PARTICIPANTS

LncRNAs were quantified from RNA-seq data from a HGT1 bladder cancer cohort that was enriched for primary micropapillary cases (15/84). Unsupervised consensus clustering of variant lncRNAs identified a three-cluster solution, which was further characterised using a panel of micropapillary-associated biomarkers, molecular subtypes, gene signatures, and survival analysis. A single-sample genomic signature was trained using lasso-penalized logistic regression to classify micropapillary-like gene-expression, as characterised by lncRNA clustering. The genomic classifier (GC) was tested on luminal tumors derived from the TCGA cohort (N = 202).

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Patient and tumor characteristics were compared between subgroups by using X² tests and two-sided Wilcoxon rank-sum tests. Primary endpoints were overall, progression-free and high-grade recurrence-free survival, calculated as the date of high-grade T1 disease at TURBT till date of death from any cause, progression, or recurrence, respectively. Survival rates were estimated using weighted Kaplan-Meier (KM) curves.

RESULTS AND LIMITATIONS

Primary micropapillary HGT1 showed decreased FGFR3, SHH, and p53 pathway activity relative to tumors with conventional urothelial carcinoma. Many bladder cancer-associated lncRNAs were downregulated in micropapillary tumors, including UCA1, LINC00152, and MALAT1. Unsupervised consensus clustering resulted in a lncRNA cluster 1 (LC1) with worse prognosis that was enriched for primary micropapillary histology and the Luminal Unstable (LumU) molecular subtype. Interestingly, LC1 appeared to better identify aggressive HGT1 disease, compared to stratifying outcomes using primary histologic characteristics. A signature trained to identify LC1 cases showed good performance in the testing cohort, identifying seven cases with significantly worse survival (p < 0.001). Limitations include the retrospective nature of the study and the lack of a validation cohort.

CONCLUSIONS

Using the lncRNA transcriptome we identified a subgroup of aggressive HGT1 bladder cancer that was enriched with micropapillary histology. These data suggest that lncRNAs can facilitate the identification of aggressive micropapillary-like tumors, potentially improving patient management.

Clinicopathological Review of Micropapillary Urothelial Carcinoma

PURPOSE OF REVIEW

This review will discuss micropapillary urothelial carcinoma with respect to biology, histopathologic characteristics, genetic and molecular features, diagnosis, clinical management, and future directions of research.

RECENT FINDINGS

Recent consensus opinion study showed only moderate interobserver reproducibility in the diagnostic criteria. The most reproducible criteria with the highest consensus were multiple nests in the same lacunar spaces. There are recent reports of high rates of intratumoral heterogeneity of ERBB2 amplification within tumor containing both micropapillary and classic urothelial components. Micropapillary urothelial carcinoma is a well-documented highly aggressive variant of urothelial carcinoma with proven worse outcomes. Accurate recognition and reporting of this pattern is critical for optimal management. Newer therapeutic strategies related to the molecular and genetic findings seen in MPUC remain to be explored further.

[ARTIFICIAL URINARY SPHINCTER IMPLANTATION AFTER ILEAL NEOBLADDER RECONSTRUCTION: A CASE REPORT]

A 62-year-old man was referred to our department for artificial urinary sphincter (AUS) implantation as treatment for total incontinence after laparoscopic radical prostatectomy. Preoperative cystoscopy revealed bladder tumor that was proven to be high-grade micropapillary urothelial carcinoma by transurethral resection. We performed radical cystectomy with ileal neobladder reconstruction, followed by AUS implantation to treat incontinence. The AUS implantation procedure was performed 5 months after total cystectomy and resulted in significant continence recovery. To date, AUS implantation after neobladder reconstruction has not been reported in Japan, although some case series have described this procedure overseas. In our view, AUS implantation is a useful therapeutic option for incontinence in patients undergoing neobladder reconstruction.

Novel Therapeutic Opportunities in Neoadjuvant Setting in Urothelial Cancers: A New Horizon Opened by Molecular Classification and Immune Checkpoint Inhibitors

Muscle invasive bladder cancer (MIBC) is a widespread malignancy with a worse prognosis often related to a late diagnosis. For early-stage MIBC pts, a multidisciplinary approach is mandatory to evaluate the timing of neoadjuvant chemotherapy (NAC) and surgery. The current standard therapy is platinum-based NAC (MVAC-methotrexate, vinblastine, doxorubicin, and cisplatin or Platinum–Gemcitabine regimens) followed by radical cystectomy (RC) with lymphadenectomy. However, preliminary data from Vesper trial highlighted that dose-dense NAC MVAC is endowed with a good pathological response but shows low tolerability. In the last few years, translational-based research approaches have identified several candidate biomarkers of NAC esponsiveness, such as ERCC2, ERBB2, or DNA damage response (DDR) gene alterations. Moreover, the recent consensus MIBC molecular classification identified six molecular subtypes, characterized by different sensitivity to chemo- or targeted or immunotherapy, that could open a novel procedure for patient selection and also for neoadjuvant therapies. The Italian PURE-01 phase II Trial extended data on efficacy and resistance to Immune Checkpoint Inhibitors (ICIs) in this setting. In this review, we summarize the most relevant literature data supporting NAC use in MIBC, focusing on novel therapeutic strategies such as immunotherapy, considering the better patient stratification and selection emerging from novel molecular classification.

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.

Histology of variants of urothelial carcinoma of the bladder: a Moroccan series of 39 cases

Background

The variant of urothelial carcinoma (UCV) is a rare and aggressive histological entity; its therapeutic management remains debated.

Methods

Between January 2017 and October 2019, 39 patients were diagnosed retrospectively with urothelial carcinoma with a histological variant. The aim of this study was to analyze the clinico-pathological and therapeutic aspects of these variants to better understand this invasive disease.

Results

In 39 cases, 36 (92%) were men and 3 (8%) were women; the average age was 62 years; 54% of patients had a ≥ cT3 stage with clinical lymph node involvement in 28% and 23% had distant metastases, 36% of patients were treated with RC and 54% by other therapeutic and 10% refused RC. No patient received neoadjuvant chemotherapy. Lymph node involvement was 28.5%. The two predominant histological types were squamous and micropapillary differentiation between the operating piece and bladder biopsy 28.5%, 30% and 21.5% and 13%, respectively. The overall survival at 20 months was 70 and 40% for RC and the other therapeutic (TURB alone or a TURB with an adjuvant), respectively. There was no significant difference in survival between the two groups (p = 0.27).

Conclusion

UCVs are heterogeneous groups of tumors which are increasingly identified due to their distinct morphological characteristics with variable clinical prognosis. Therapeutic management is not in favor of cystectomy in our study. However, a prospective study using a larger cohort is still necessary to validate our results.

The effect of neoadjuvant chemotherapy among patients undergoing radical cystectomy for variant histology bladder cancer: A systematic review

Objective

To systematically review the evidence about the effect of neoadjuvant chemotherapy (NAC) for muscle-invasive bladder cancer (MIBC) with pure urothelial carcinoma (pUC) in radical cystectomy (RC) candidates affected by variant histology (VH) bladder cancer.

Methods

A review of the current literature was conducted through the Medline and National Center for Biotechnology Information (NCBI) PubMed, Scopus databases in May 2020. The updated Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed for this systematic review. Keywords used were ‘bladder cancer’, ‘bladder carcinoma’, ‘bladder tumour’ and ‘bladder cancer variants’ and ‘neoadjuvant chemotherapy’. Only original articles in English published after 2000 and reporting oncological outcomes a series of more than five patients with VH were included. We excluded series in which the oncological outcomes of patients with pUC and VH were undistinguishable.

Results

The literature search identified 2231 articles. A total of 51 full-text articles were assessed for eligibility, with 17 eventually considered for systematic review, for a cohort of 450,367 patients, of which 5010 underwent NAC + RC. The median age at initial diagnosis ranged from 61 to 71 years. Most patients received cisplatin-gemcitabine, methotrexate-vinblastine-adriamycin-cisplatin, or carboplatin-based chemotherapy. Only one study reported results of neoadjuvant immunotherapy. The median follow-up ranged from 1 to 120 months. The results showed that squamous cell carcinoma (SCC) is less sensitive to NAC than pUC and that SCC predicts poorer prognosis. NAC was found to be a valid approach in treating small cell carcinoma and may have potential benefit in micropapillary carcinoma.

Conclusions

NAC showed the best oncological outcomes in small cell variants and micropapillary carcinoma, while NAC survival benefit for SCC and adenocarcinoma variants needs further studies. Drawing definite considerations on the efficacy of NAC in VH is complicated due to the heterogeneity of present literature. Present results need to be confirmed in randomised controlled trials.

Gene Expression Profiling of Muscle-Invasive Bladder Cancer With Secondary Variant Histology

OBJECTIVES

To determine the potential impact of the presence of secondary variant histology on the gene expression profiles of muscle-invasive bladder cancer (MIBC) tumors.

METHODS

For six tumors, revised samples were collected from urothelial and secondary variant components (cohort A). The commercial cohort (cohort B) consisted of the anonymized gene expression profiles of 173 patients with MIBC. Samples were obtained from the clinical use of the Decipher Bladder test that were available as part of the Decipher GRID prospective registry (NCT02609269). Secondary variant presence in cohort B was abstracted from institutional pathology reports. For the commercial cohort, only the urothelial carcinoma component was profiled.

RESULTS

Molecular subtyping of both urothelial and variant components found micropapillary and nested cases were classified as a luminal subtype. Conversely, the sarcomatoid and small cell cases were classified as basal/squamous or neuroendocrine-like, respectively. For cohort B, 50 (29%) of 173 cases had reported secondary variant histology. Cases with squamous variant had basal profiles, small cell cases expressed neuronal markers, and micropapillary cases were classified as luminal. Sarcomatoid tumors had robust epithelial-mesenchymal transition marker expression.

CONCLUSIONS

Our data suggest that in MIBC with secondary variant, the urothelial component can demonstrate an expression profile that closely resembles the variant component.

Novel Histologic Classification of Small Tumor Cell Nests for Lung Adenocarcinoma With Prognostic and Etiological Significance: Small Solid Nests and Pure Micropapillary Nests

Small tumor cell nests such as micropapillary nests are histologic poor prognostic markers for adenocarcinomas of various organs, including the lung. However, for the lung, the association of micropapillary patterns with smoking is controversial, which may be because of a vague definition of micropapillary patterns. This study clarifies the implications of small tumor cell nests by introducing a new dichotomic classification based on the glandular polarity of tumor cells: pure micropapillary nests (pMPs), preserving glandular polarity, and small solid nests (SSNs), lacking polarity. We examined the clinicopathologic factors in 436 resected adenocarcinomas, and analyzed the overall survival between groups classified by either the presence or absence of pMPs and SSNs. pMP was positively associated with nonsmoking-related features such as epidermal growth factor receptor mutations and thyroid transcription factor 1 expression. By contrast, SSN was positively associated with smoking-related features such as KRAS mutations and hepatocyte nuclear factor-4a expressions. Besides, pMP and SSN were significant and independent indicators of poor prognosis in all stages. SSN was an indicator in stage I too, whereas pMP was not. Furthermore, prognoses of the group with SSN were significantly worse than those of pMP-only group. In conclusion, the present study has revealed 2 completely different patterns of small tumor cell nests in lung adenocarcinoma, the nonsmoking-related pMPs, and the smoking-related SSNs, by considering glandular polarity. MPP should include only pMPs, and SSNs should be in a solid pattern. This novel classification might boast clinical significance as a potent poor prognostic marker as well as a factor reflecting etiological and genetic characters.

Accuracy of Transurethral Resection of the Bladder in Detecting Variant Histology of Bladder Cancer Compared with Radical Cystectomy

BACKGROUND

Correct identification of variant histologies (VHs) of bladder cancer (BCa) at transurethral resection of the bladder (TURB) could drive the subsequent treatment.

OBJECTIVE

To evaluate the concordance in detecting VHs between TURB and radical cystectomy (RC) specimens in BCa patients.

DESIGN, SETTING, AND PARTICIPANTS

We retrospectively analyzed 1881 BCa patients who underwent TURB and subsequent RC at seven tertiary care centers between 1980 and 2018. VHs were classified as sarcomatoid, lymphoepithelioma-like, neuroendocrine, squamous, micropapillary, glandular, adenocarcinoma, nested, and other variants.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Concordance between TURB and RC was defined as the ability to achieve histological subtypes at TURB confirmed at RC specimen, and was expressed according to Cohen's kappa coefficient.

RESULTS AND LIMITATIONS

Of the patients, 14.6% and 21% were diagnosed with VH at TURB and RC specimens, respectively. The most common VHs at TURB were squamous, neuroendocrine, and micropapillary carcinoma (5.2%, 1.5%, and 1.5%, respectively). At RC, the most frequent VHs were squamous, micropapillary, and sarcomatoid carcinoma (7.2%, 3.0%, and 2.7%, respectively). The overall concordance in detecting VH was defined as slight concordance (coefficient: 0.18). Moderate concordance was found for neuroendocrine, adenocarcinoma, and squamous carcinoma (coefficient: 0.49, 0.47, and 0.41, respectively). Micropapillary, glandular, and other variants showed slight concordance (coefficient: 0.05, 0.17, and 0.12, respectively), while nested and sarcomatoid carcinoma showed fair concordance (coefficient: 0.32 and 0.26, respectively). Results may be limited by the absence of centralized pathological analysis.

CONCLUSIONS

A non-negligible percentage of patients were diagnosed with VH at both TURB and RC. TURB showed relatively low accuracy, ranging from poor to moderate, in detecting VHs. Our study underlines the need of additional diagnostic tools in order to identify VHs properly at precystectomy time and to improve patient survival outcomes.

PATIENT SUMMARY

In this report, we underlined the low accuracy of transurethral resection of the bladder in detecting variant histologies and the need for additional diagnostic tools.

Non-Muscle Invasive Bladder Cancer with Variant Histology: Biological Features and Clinical Implications

BACKGROUND

The most common bladder cancer (BC) histotype is pure urothelial carcinoma (UC), which may undergo divergent differentiation in some cases. Variant histology (VH) presents along variable morphologies, either single or combined between them or with pure UC. From a clinical standpoint, the vast majority of BC is diagnosed at non-invasive or minimally invasive stages, namely as non-muscle invasive BC (NMIBC). There is a wide range of therapeutic options for patients with NMIBC, according to their clinical and pathological features. However, current risk stratification models do not show optimal effectiveness. Evidence from the literature suggests that VH has peculiar biological features, and may be associated with poorer survival outcomes compared to pure UC.

SUMMARY

In order to describe the biological features and prognostic/predictive role of VH in NMIBC, and to discuss current treatment options, we performed a systematic literature search through multiple databases (PubMed/Medline, Google Scholar) for relevant articles according to the following terms, single and/or in combination: "non-muscle invasive bladder cancer," "variant histology," "micropapillary variant," "glandular differentiation," "squamous differentiation," "nested variant," "plasmacytoid variant," and "sarcomatoid variant." We extracted 99 studies including original articles, reviews, and systematic reviews, and subsequently analyzed data from 16 studies reporting on the outcome of NMIBC with VH. We found that the relative rarity of these forms as well as the heterogeneity in study populations and therapeutic protocols results in conflicting findings overall. Key Messages: The presence of VH should be taken into account when counseling a patient with NMIBC, since it may upgrade the disease to high-risk tumor and thus warrant a more aggressive treatment.

Association of patients' sex with treatment outcomes after intravesical bacillus Calmette-Guérin immunotherapy for T1G3/HG bladder cancer

Purpose

To investigate the association of patients’ sex with recurrence and disease progression in patients treated with intravesical bacillus Calmette–Guérin (BCG) for T1G3/HG urinary bladder cancer (UBC).

Materials and methods

We analyzed the data of 2635 patients treated with adjuvant intravesical BCG for T1 UBC between 1984 and 2019. We accounted for missing data using multiple imputations and adjusted for covariate imbalance between males and females using inverse probability weighting (IPW). Crude and IPW-adjusted Cox regression analyses were used to estimate the hazard ratios (HR) with their 95% confidence intervals (CI) for the association of patients’ sex with HG-recurrence and disease progression.

Results

A total of 2170 (82%) males and 465 (18%) females were available for analysis. Overall, 1090 (50%) males and 244 (52%) females experienced recurrence, and 391 (18%) males and 104 (22%) females experienced disease progression. On IPW-adjusted Cox regression analyses, female sex was associated with disease progression (HR 1.25, 95%CI 1.01–1.56, p = 0.04) but not with recurrence (HR 1.06, 95%CI 0.92–1.22, p = 0.41). A total of 1056 patients were treated with adequate BCG. In these patients, on IPW-adjusted Cox regression analyses, patients’ sex was not associated with recurrence (HR 0.99, 95%CI 0.80–1.24, p = 0.96), HG-recurrence (HR 1.00, 95%CI 0.78–1.29, p = 0.99) or disease progression (HR 1.12, 95%CI 0.78–1.60, p = 0.55).

Conclusion

Our analysis generates the hypothesis of a differential response to BCG between males and females if not adequately treated. Further studies should focus on sex-based differences in innate and adaptive immune system and their association with BCG response.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-021-03653-1.

Prognostic value of albumin to globulin ratio in non-muscle-invasive bladder cancer

Purpose

To investigate the prognostic value of preoperative serum albumin to globulin ratio (AGR) in patients with non-muscle-invasive bladder cancer (NMIBC) treated with transurethral resection of bladder tumor (TURB) with or without intravesical therapy (IVT).

Materials and methods

We retrospectively reviewed 1,096 consecutive patients with NMIBC. Levels of albumin and globulin were obtained before TURB and used to calculate the preoperative AGR level. Multivariable Cox regression analyses were performed to assess the prognostic effect of preoperative AGR on oncologic outcomes. Subgroup analyses were performed in patients based on the European Association of Urology (EAU) risk groups for NMIBC.

Results

Low AGR levels were observed in 389 (35.5%) patients. The median follow-up was 63.7 months (IQR 25.3–111). On multivariable Cox regression analysis, low AGR was associated with increased risk of progression to muscle-invasive BCa (MIBC) (HR 1.81, 95% CI 1.22–2.68, P = 0.003). The addition of AGR only minimally improved the discrimination ability of a base model that included established clinicopathologic features (C-index = 0.7354 vs. C-index = 0.7162). Low preoperative AGR was not significantly associated with the risk of disease recurrence (P = 0.31). In subgroup analyses based on patients’ EAU risk groups, low preoperative AGR was not associated with recurrence-free survival (RFS) (P = 0.59) or progression-free survival (PFS) (P = 0.22) in any of the risk groups. Additionally, in patients treated with Bacillus Calmette–Guerin (BCG) for intermediate- or high-risk NMIBC, low AGR failed to predict disease recurrence or progression.

Conclusion

Preoperative serum AGR levels independently predicted the risk of disease progression in patients with NMIBC. However, it was not found to be associated with either RFS or PFS in NMIBC patients based on their EAU risk group. This marker seems to have a limited role in NMIBC at the present time. However, further research is needed to investigate this marker in combination with other systemic inflammatory markers to help improve prediction in this heterogeneous group of patients.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-020-03586-1.

Genetic Differences Between Bladder and Upper Urinary Tract Carcinoma: Implications for Therapy

CONTEXT

Bladder urothelial carcinoma (BUC) and upper tract urothelial carcinoma (UTUC) have genetic differences, which may influence therapy.

OBJECTIVE

The aim of the current review was to summarize the current genetic understanding of upper tract and BUC.

EVIDENCE ACQUISITION

PubMed, Cochrane, and Web of Science online databases were searched systematically up to February 2020, using the following keywords: urothelial carcinomas, upper urinary tract, renal pelvis, ureter, bladder cancer, and genetics.

EVIDENCE SYNTHESIS

UTUC and BUC share mutations in similar genes, such as FGFR3, TP53, and HRAS, and epigenetic genes, such as KDM6A and KMT2A-C, but at varying frequencies. Furthermore, subtyping of UTUC and BUC has identified similar expression subtypes, but UTUC is more often luminal with more T-cell depletion. Clonal studies indicate that BUC after UTUC is also likely luminal, while UTUC after BUC is often basal.

CONCLUSIONS

UTUC and BUC share many genomic alterations, but at different frequencies, which recapitulate with their metachronous recurrences. These differences likely contribute to the behavior of these two cancers and imply that they and their metachronous recurrences should be treated as two related yet distinct entities.

PATIENT SUMMARY

Urothelial carcinoma of the bladder has distinct genomic features, which are different from distinct genomic features of urothelial carcinoma of the renal pelvis and/or ureter. These features can be used for tailored treatment options specific to tumors of different locations.

Ureteral and urethral recurrence after radical cystectomy: a systematic review

PURPOSE OF REVIEW

The clinical significance of ureteral and urethral recurrence in patients treated with radical cystectomy for bladder cancer is scarce and heterogeneous. The aim of the current review is to summarize the recent literature on incidence, diagnosis and oncologic outcomes of ureteral and urethral recurrences after radical cystectomy.

RECENT FINDINGS

Frozen section analysis (FSA) of ureteral margin had a sensitivity and specificity of 69-77 and 83-96%, respectively. Considering the ureteral margin, the reported sensitivity and specificity were 33-93 and 99-100%, respectively. Transurethral biopsy of the prostatic urethra might help in counseling patients' treatment, although its accuracy and prognostic role is highly questionable. In patients treated with radical cystectomy, recurrence of the urethra or ureteral are rare, occurring approximately in 5% of patients. During the follow-up, urinary cytology and cross-sectional imaging improve the early detection of recurrence in asymptomatic patients, although the majority are diagnosed for symptomatic presentation. Their use should be tailored to the patient's risk of ureteral and/or urethral recurrence. Urethrectomy is indicated in case of singular urethral recurrence, whereas no clear data exists regarding the best management of ureteral recurrence, except surgical removal.

SUMMARY

Intraoperative FSA of ureters and urethra share good specificity but poor sensitivity. Recurrence at urethra and upper tract are rare and discordant data exists regarding survival outcomes. Oncologic surveillance after radical cystectomy with the aim to detect these recurrences should be tailored to the individualized patient's risk.

The optimal management of variant histology in muscle invasive bladder cancer

Bladder cancer is a heterogenous disease that is associated with tangible mortality in muscle invasive disease. The WHO 2016 classification of urothelial tumours reflects the contemporary approach towards histological variants in bladder cancer, including variants of urothelial carcinoma (UC) and non-urothelial variants. This review focuses on variant histology in UC, and discusses the importance of accurate histological diagnosis, and subsequent risk stratification and therapeutic decision making based on proper variant recognition. Most urothelial variants are associated with poorer outcomes compared to conventional UC, although some perform reasonably better. However, high quality evidence detailing optimal treatment and survival outcomes are still lacking in literature, due to the rarity of these cases.

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.

Frailty impact on postoperative complications and early mortality rates in patients undergoing radical cystectomy for bladder cancer: a systematic review

Objective: To assess the prevalence of frailty, a status of vulnerability to stressors leading to adverse health events, in bladder cancer patients undergoing radical cystectomy (RC), and test the impact of frailty measurements on postoperative adverse outcomes.

Methods: A systematic review of English-language articles published up to April 2020 was performed. Electronic databases were searched to quantify the frailty prevalence in RC patients and assess the predictive ability of frailty indexes on RC-related outcomes as postoperative complications, early mortality, hospitalization length (LOS), costs, discharge dispositions, readmission rate.

Results: Eleven studies were selected. Patients’ frailty was identified by Johns Hopkins indicator (JHI) in two studies, 11-item modified Frailty Index (mFI) in four, 5-item simplified FI (sFI) in three, 15-point mFI in one, Fried Frailty Criteria in one. Considering all the frailty measurements applied, 8% and 31% of patients were frail or pre-frail, respectively. Frail (43%) and pre-frail patients (35%) were more at risk of major complications compared to non-frail (27%) using sFI; with JHI the percentages of frail and non-frail were 53% versus 19%. According to JHI and mFI frailty was related to longer LOS and higher costs. JHI identified that 3% of frail patients experience in-hospital mortality versus 1.5% of non-frail. Finally, using sFI, frail (28%), and pre-frail (19%) were more likely to be discharged non-home compared to non-frail patients (8%) and had a higher risk of 30-day mortality (4% and 2% versus 1%).

Conclusions: Almost half of RC patients were frail or pre-frail, conditions significantly related to an increased risk of postoperative adverse events with higher rates of major complications and early mortality. The most-used frailty index was mFI, while JHI and sFI resulted the most reliable to predict early postoperative RC-related adverse outcomes and should be routinely included in clinical practice after better standardization throughout prospective comparative studies.

Abbreviations: ACG: Adjusted Clinical Groups; ACS: American College Surgeons; AUC: area under the curve; BCa: bladder cancer; CCI: Charlson Comorbidity Index; CSHA-FI: Canadian Study of Health and Aging Frailty Index; CCS: Clavien-Dindo Classification Score; ERAS: Enhanced Recovery After Surgery; FFC: Fried Frailty Criteria; (e)(m)(s)FI: (extended) (modified) (simplified) Frailty Index; ICU: intensive care unit; IQR: interquartile range; (p)LOS: (prolonged) length of hospital stay; NSQIP: National Surgical Quality Improvement Program; OR: odds ratio; (O)PN: (open) partial nephrectomy; PRISMA: Preferred Reporting Items for Systematic reviews and Meta-Analyses; (O)(RA)RC: (open)(robot-assisted) radical cystectomy; (O)RN: (open) radical nephrectomy; ROC: receiver operating characteristic; RNU: radical nephroureterectomy; (R)RP: (retropubic) radical prostatectomy; RR: relative risk; THCs: total hospital charges; nephrectomy; UD: urinary diversion

Clinical Characteristics and Prognosis of Rare Histological Variants of Bladder Cancer: A Single-Center Retrospective Study from China

Objective

To investigate the clinical characteristics and prognosis of patients with rare histological variants of bladder cancer (RHV-BC) in China.

Materials and Methods

Patients diagnosed as bladder carcinoma with RHV in our center, from March 2009 and April 2019, were included. The univariate and multivariate COX regression model were used to evaluate the association between clinical characteristics and overall survival (OS).

Results

A total of 54 (1.4%) patients with RVH-BC were identified from 3803 potential patients with bladder cancer. The RHV classifications included micropapillary variant (MPV), sarcomatoid variant (SAV), neuroendocrine variant (NEV), nested variant (NV), plasmacytoid variant (PCV), and lymphoepithelioma-like variant (LEV), which were found in 19, 18, seven, six, three, and one patient, respectively. The mean of recurrence-free survival (RFS), cancer-specific survival (CSS), and OS of patients were 18.8 months, 37.0 months and 36.0 months, respectively. The multivariable analyses indicated that metastasis and T ≥2 were independent risk factors of OS. Besides, 84.4% (27/32) of patients who were receiving intravesical therapies (IVT) suffered recurrence. Patients with adjuvant chemotherapy (AC) had a recurrence rate of 64.7% (11/17).

Conclusion

T≥2 and metastasis were independent risk factors of OS in patients with RHV-BC. Considering a high recurrence following transurethral resection of bladder tumor (TURBT) and IVT, early radical cystectomy (RC) might be performed for patients with RHV-BC.

Urothelial carcinoma: variant histology, molecular subtyping, and immunophenotyping significant for treatment outcomes

Although urothelial carcinoma (UC) has been recognised as a homogenous disease entity until recently, it exhibits widely diverse histological variants. Recent studies have revealed that some histological variants may serve as markers of very high risk for advanced cancers and poor prognoses. Certain histological variants can generate a pathological T stage, which may result in unnecessary surgery. Though platinum based chemotherapy is the standard treatment, the use of immune checkpoint inhibitors (ICIs) for UC treatment has become a major trend in oncology. UCs showing specific histological variants have responded exceptionally well to chemotherapy and ICIs. Currently, molecular studies base molecular classification on gene expression profile signatures in order to make diagnoses or predict responses to chemotherapies and ICIs. Notably, some histological variants correlate with specific molecular subtypes. The usefulness of immunophenotyping for classification purposes was recognised only recently. Immunophenotypes are classified into three categories according to lymphocyte distribution in or around the cancer cell nest: desert, excluded, and inflamed. This immunophenotyping has been increasingly shown to be of value in predicting the response to ICIs. This review describes the morphological characteristics of histological variants as well as the advantages and limitations in determining them, with particular reference to clinical benefits. Subsequently, we describe the concept of molecular classification and immunophenotypes, and their morphological features, which are easily interpreted and amenable to daily practice via hematoxylin and eosin staining. We also consider the clinical advantages, limitations, and issues encountered while using these in routine clinical practice.

Response to Neoadjuvant Chemotherapy and Survival in Micropapillary Urothelial Carcinoma: Data From a Tertiary Referral Center and the Surveillance, Epidemiology, and End Results (SEER) Program

BACKGROUND

Micropapillary urothelial carcinoma (MPC) is a rare urothelial carcinoma variant with conflicting data guiding clinical practice. In this study, we explored oncologic outcomes in relation to neoadjuvant chemotherapy (NAC) in a retrospective cohort of patients with MPC, alongside data from Surveillance, Epidemiology, and End Results (SEER)-Medicare.

PATIENTS AND METHODS

We retrospectively identified patients with MPC or conventional urothelial carcinoma (CUC) without any variant histology undergoing radical cystectomy (RC) in our institution (2003-2018). SEER-Medicare was also queried to identify patients diagnosed with MPC (2004-2015). Clinicopathologic data and treatment modalities were extracted. Overall survival (OS) was estimated with the Kaplan-Meier method. Mann-Whitney-Wilcoxon and chi-square tests were used for comparative analysis and Cox regression for identifying clinical covariates associated with OS.

RESULTS

Our institutional database yielded 46 patients with MPC and 457 with CUC. In SEER-Medicare, 183 patients with MPC were identified, and 63 (34%) underwent RC. In the institutional cohort, patients with MPC had significantly higher incidence of cN+ (17% vs. 8%), pN+ stage (30% vs. 17%), carcinoma-in-situ (43% vs. 25%), and lymphovascular invasion (30% vs. 16%) at RC versus those with CUC (all P < .05). Pathologic complete response (ypT0N0) to NAC was 33% for MPC and 35% for CUC (P = .899). Median OS was lower for institutional MPC versus CUC in univariate analysis (43.6 vs. 105.3 months, P = .006); however, MPC was not independently associated with OS in the multivariate model. Median OS was 25 months in the SEER MPC cohort for patients undergoing RC, while NAC was not associated with improved OS in that group.

CONCLUSION

Pathologic response to NAC was not significantly different between MPC and CUC, while MPC histology was not an independent predictor of OS. Further studies are needed to better understand biological mechanisms behind its aggressive features as well as the role of NAC in this histology variant.

Prediction of the Need for an Extended Lymphadenectomy at the Time of Radical Cystectomy in Patients with Bladder Cancer

BACKGROUND

A prospective randomized trial (LEA AUO AB 25/02) found no survival benefit in extended compared with limited pelvic lymph node dissection (PLND) templates in bladder cancer (BCa) patients treated with radical cystectomy (RC). However, the rate of lymph node invasion (LNI) in the standard and extended templates was lower than estimated.

OBJECTIVE

To assess the accuracy of preoperative clinical and pathological parameters to predict LNI and to develop a model to preoperatively select candidates for the extended PLND templates.

DESIGN, SETTING, AND PARTICIPANTS

A total of 903 BCa patients treated at a single institution were retrospectively identified. The primary outcome was to identify preoperatively the risk of LNI to tailor the type of PLND. The extended PLND templates consisted in the removal of pelvic lymph nodes together with the common iliac, presacral, para-aortocaval, interaortocaval, and paracaval sites up to the inferior mesenteric artery.

INTERVENTION

A total of 903 BCa patients were treated with RC and bilateral extended PLND templates.

OUTCOME MEASUREMENTS AND STATISTICAL ANALYSIS

Several models predicting LNI were evaluated using the area under the receiver operating characteristic curve (AUC), calibration plots and decision curve analyses. A nomogram predicting LNI in the extended pattern was developed and validated internally.

RESULTS AND LIMITATIONS

Overall, 55 patients (6.1%) had LNI in the extended PLND templates at RC. The median number of nodes removed was 19 (interquartile range: 13-26). A model including age, clinical T stage, clinical node stage, lymphovascular invasion, and presence of carcinoma in situ at the last transurethral resection before RC was developed. The AUC of this model is 73%. Using a cutoff of 3%, 108 extended PLNDs (12%) would be spared and only two LNIs (3%) would be missed. The main limitations of our model are the retrospective nature of the data, lack of external validation, and low rate of LNI.

CONCLUSIONS

This is the first proposed model to predict LNI in the extended PLND templates. This model might help urologists identify which patients might benefit from an extended PLND at the time of RC, reserving a standard PLND for all the others.

PATIENT SUMMARY

We developed the first nomogram to predict lymph node invasion (LNI) in the extended pelvic lymph node dissection templates in bladder cancer patients treated with radical cystectomy. The adoption of our model to identify candidates for the extended pelvic lymph node dissection templates could avoid up to 12% of these procedures at the cost of missing only 3% of patients with LNI.

Current Management of Localized Muscle-Invasive Bladder Cancer: A Consensus Guideline from the Genitourinary Medical Oncologists of Canada

BACKGROUND: Despite recent advances in the management of muscle-invasive bladder cancer (MIBC), treatment outcomes remain suboptimal, and variability exists across current practice patterns. OBJECTIVE: To promote standardization of care for MIBC in Canada by developing a consensus guidelines using a multidisciplinary, evidence-based, patient-centered approach who specialize in bladder cancer. METHODS: A comprehensive literature search of PubMed, Medline, and Embase was performed; and most recent guidelines from national and international organizations were reviewed. Recommendations were made based on best available evidence, and strength of recommendations were graded based on quality of the evidence. RESULTS: Overall, 17 recommendations were made covering a broad range of topics including pathology review, staging investigations, systemic therapy, local definitive therapy and surveillance. Of these, 10 (59% ) were level 1 or 2, 7 (41% ) were level 3 or 4 recommendations. There were 2 recommendations which did not reach full consensus, and were based on majority opinion. This guideline also provides guidance for the management of cisplatin-ineligible patients, variant histologies, and bladder-sparing trimodality therapy. Potential biomarkers, ongoing clinical trials, and future directions are highlighted. CONCLUSIONS: This guideline embodies the collaborative expertise from all disciplines involved, and provides guidance to further optimize and standardize the management of MIBC.