Neoadjuvant chemotherapy prior to radical cystectomy for muscle-invasive bladder cancer with variant histology

The role of neoadjuvant chemotherapy for patients with variant histology muscle invasive bladder cancer undergoing robotic cystectomy: Data from the International Robotic Cystectomy Consortium

OBJECTIVE

To assess the role of neoadjuvant chemotherapy (NAC) before robot-assisted radical cystectomy (RARC) for patients with variant histology (VH) muscle-invasive bladder cancer (MIBC).

METHODS

Retrospective review of 988 patients who underwent RARC (2004-2023) for MIBC. Primary outcomes included the utilization of NAC among this cohort of patients, frequency of downstaging, and discordance between preoperative and final pathology in terms of the presence of VH. Secondary outcomes included disease-specific (DSS), recurrence-free (RFS), and overall survival (OS).

RESULTS

A total of 349 (35%) had VH on transurethral resection or at RARC. The 4 most common VH subgroups were squamous (n = 94), adenocarcinoma (n = 64), micropapillary (n = 34), and sarcomatoid (n = 21). There was no difference in OS (log-rank: P = 0.43 for adenocarcinoma, P = 0.12 for micropapillary, P = 0.55 for sarcomatoid, P = 0.29 for squamous), RFS (log-rank: P = 0.25 for adenocarcinoma, P = 0.35 for micropapillary, P = 0.83 for sarcomatoid, P = 0.79 for squamous), or DSS (log-rank P = 0.91 for adenocarcinoma, P = 0.15 for micropapillary, 0.28 for sarcomatoid, P = 0.92 for squamous) among any of the VH based on receipt of NAC. Patients with squamous histology who received NAC were more likely to be downstaged on final pathology compared to those who did not (P < 0.01).

CONCLUSION

Our data showed no significant difference in OS, RFS, or DSS for patients with VH MIBC cancer who received NAC before RARC. Patients with the squamous variant who received NAC had more pathologic downstaging compared to those who did not. The role of NAC among patients with VH is yet to be defined. Results were limited by small number in each individual group and lack of exact proportion of VH.

Impact of Neoadjuvant Chemotherapy on Pathologic Downstaging in Patients With Variant Histology Undergoing Radical Cystectomy

INTRODUCTION

Variant histology (VH) bladder cancer is often associated with poor outcomes and the role of neoadjuvant chemotherapy (NAC) remains incompletely defined. Our objective was to determine comparative pathologic downstaging at radical cystectomy (RC) following NAC for patients with and without VH.

PATIENTS AND METHODS

Patients who underwent RC at 2 tertiary referral centers (1996-2018) were included. Patients with VH (sarcomatoid, nested, micropapillary, plasmacytoid) were matched 1:2 to patients with pure urothelial carcinoma by age, sex, clinical T (cT)stage, clinical N (cN)stage, cystectomy year and receipt of NAC. The primary outcome was pathologic downstaging (pT-stage < cT-stage). The differential impact of NAC on pathologic downstaging between VH and non-VH was assessed using multivariable logistic regression with interaction analysis.

RESULTS

225 VH and 437 non-VH patients were included. One hundred twenty-eight of six hundred sixty-two (19.3%) patients experienced downstaging, including 54/121 (44.6%) patients who received NAC and 74/542 (13.2%) patients who did not (P < .01). Rates of downstaging after NAC for subgroups were: 45/78 (57.7%) urothelial, 3/8 (37.5%) sarcomatoid, 2/12 (16.7%) nested, 3/14 (21.4%) micropapillary, and 1/8 (12.5%) plasmacytoid. Collectively, 9/42 (21.4%) of VH patients who received NAC were downstaged. On multivariable analyses, NAC was associated with increased likelihood of downstaging in the overall cohort (OR 5.25, 95% CI, 3.29-8.36, P < .0001) and this effect was not modified by VH versus non-VH histology (P = .13 for interaction). VH patients had worse survival outcomes compared to non-VH (P < 0.01 for all).

CONCLUSION

When comparing patients with VH to matched pure urothelial carcinoma controls, VH did not have an adverse effect on downstaging following NAC. VH patients should not be excluded from NAC if otherwise eligible.

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.

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.

European Association of Urology Guidelines on Muscle-invasive and Metastatic Bladder Cancer: Summary of the 2023 Guidelines

CONTEXT

We present an overview of the updated 2023 European Association of Urology (EAU) guidelines for muscle-invasive and metastatic bladder cancer (MMIBC).

OBJECTIVE

To provide practical evidence-based recommendations and consensus statements on the clinical management of MMIBC with a focus on diagnosis and treatment.

EVIDENCE ACQUISITION

A broad and comprehensive scoping exercise covering all areas of the MMIBC guidelines has been performed annually since 2017. Searches cover the Medline, EMBASE, and Cochrane Libraries databases for yearly guideline updates. A level of evidence and strength of recommendation are assigned. The evidence cutoff date for the 2023 MIBC guidelines was May 4, 2022.

EVIDENCE SYNTHESIS

Patients should be counselled regarding risk factors for bladder cancer. Pathologists should describe tumour and lymph nodes in detail, including the presence of histological subtypes. The importance of the presence or absence of urothelial carcinoma (UC) in the prostatic urethra is emphasised. Magnetic resonance imaging (MRI) of the bladder is superior to computed tomography (CT) for disease staging, specifically in differentiating T1 from T2 disease, and may lead to a change in treatment approach in patients at high risk of an invasive tumour. Imaging of the upper urinary tract, lymph nodes, and distant metastasis is performed with CT or MRI; the additional value of flurodeoxyglucose positron emission tomography/CT still needs to be determined. Frail and comorbid patients should be evaluated by a multidisciplinary team. Postoperative histology remains the most important prognostic variable, while circulating tumour DNA appears to be an interesting predictive marker. Neoadjuvant systemic therapy remains cisplatin-based. In motivated and selected women and men, sexual organ-preserving cystectomy results in better functional outcomes without compromising oncological outcomes. Robotic and open cystectomy have comparable outcomes and should be combined with (extended) lymph node dissection. The diversion type is an individual choice after taking patient and tumour characteristics into account. Radical cystectomy remains a highly complex procedure with considerable morbidity and risk of mortality, although lower rates are observed for higher hospital volumes (>20 cases/yr). With proper patient selection, trimodal therapy (chemoradiation) has comparable outcomes to radical cystectomy. Adjuvant chemotherapy after surgery improves disease-specific survival and overall survival (OS) in patients with high-risk disease who did not receive neoadjuvant treatment, and is strongly recommended. There is a weak recommendation for adjuvant nivolumab, as OS data are not yet available. Health-related quality of life should be assessed using validated questionnaires at baseline and after treatment. Surveillance is needed to monitor for recurrent cancer and functional outcomes. Recurrences detected on follow-up seem to have better prognosis than symptomatic recurrences.

CONCLUSIONS

This summary of the 2023 EAU guidelines provides updated information on the diagnosis and treatment of MMIBC for incorporation into clinical practice.

PATIENT SUMMARY

The European Association of Urology guidelines panel on muscle-invasive and metastatic bladder cancer has released an updated version of the guideline containing information on diagnosis and treatment of this disease. Recommendations are based on studies published up to May 4, 2022. Surgical removal of the bladder and bladder preservation are discussed, as well as updates on the use of chemotherapy and immunotherapy in localised and metastatic disease.

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.

How Do Molecular Classifications Affect the Neoadjuvant Treatment of Muscle-Invasive Urothelial Carcinoma?

Despite the significant improvements in the field of oncological treatments in recent decades, and the advent of targeted therapies and immunotherapy, urothelial carcinoma of the bladder remains a highly heterogeneous and difficult-to-treat neoplasm with a poor prognosis. In this context, owing to the new methods of genomic sequencing, numerous studies have analyzed the genetic features of muscle-invasive bladder cancer, providing a consensus set of molecular classes, to identify malignancies that may respond better to specific treatments (standard chemotherapy, immunotherapy, target therapy, local-regional treatment, or combinations) and improve the survival. The aim of the current review is to provide an overview of the current status of the molecular landscape of muscle-invasive bladder cancer, focusing our attention on therapeutic and prognostic implications in order to select the most effective and tailored therapeutic regimen for the individual patient.

Extrapulmonary Neuroendocrine Carcinomas: Current Management and Future Perspectives

Neuroendocrine carcinomas (NECs) are poorly differentiated and highly aggressive epithelial neuroendocrine neoplasms. The most common primary site is the lung, but they may arise in every organ. Approximately 37% of extrapulmonary NECs (EP-NECs) occur in the gastroenteropancreatic (GEP) tract, followed by the genitourinary (GU) system and gynecological tract. As a result of their rarity, there is scant evidence to guide treatment recommendations, and a multidisciplinary approach is essential for the management of such patients. Platinum-based chemotherapy currently represents the standard of care for EP-NECs of any site, mirroring the management of small-cell lung cancer (SCLC), but further approaches are still under investigation. Indeed, ongoing trials evaluating targeted therapies, immune checkpoint inhibitors (ICIs), and radionuclide therapy could provide potentially breakthrough therapeutic options. Given the relative dearth of evidence-based literature on these orphan diseases, the aim of this review is to provide an overview of the pathology and current treatment options, as well as to shed light on the most pressing unmet needs in the field.

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.

Impact of Squamous Histology on Clinical Outcomes and Molecular Profiling in Metastatic Urothelial Carcinoma Patients Treated With Immune Checkpoint Inhibitors or Enfortumab Vedotin

INTRODUCTION

Urothelial carcinoma with squamous differentiation (UCS) is associated with increased resistance to chemotherapy, but outcomes associated with newer therapies approved in this space over the last 5 to 10 years are less well defined. We investigated clinical outcomes and molecular profiling of patients with UCS treated with an immune checkpoint inhibitor (ICI) and/or Enfortumab vedotin (EV).

PATIENTS AND METHODS

We undertook a retrospective analysis of UC patients treated with ICI and/or EV. Objective response rate (ORR), progression free survival (PFS) and overall survival (OS) were compared between pure UC (pUC) and UCS using X2 and log-rank tests, respectively. Prevalence of the most commonly detected somatic alterations were also compared between the 2 histologic subgroups.

RESULTS

A total of 160 patients (40 UCS, 120 pUC) were identified for this analysis. Among 151 patients treated with ICI (38 UCS, 113 pUC), UCS patients had a shorter mPFS (1.9 vs. 4.8 months, P < 0.01) and mOS (9.2 vs. 20.7 months, P < 0.01) compared to pUC. Among 37 patients treated with EV (12 UCS, 25 pUC), UCS patients had a lower ORR (17% vs. 70%, P < 0.01) and shorter mPFS (3.4 vs. 15.8 months, P < 0.01). UCS samples were enriched for CDKN2A, CDKN2B, PIK3CA, while pUC samples were enriched for ERBB2 alterations.

CONCLUSION

In this single-center retrospective analysis, patients with UCS had a distinct somatic genomic profile relative to patients with pUC. Patients with UCS also had inferior outcomes to ICIs and EV compared to patients with pUC.

The Impact of Variant Histology in Patients with Urothelial Carcinoma Treated with Radical Cystectomy: Can We Predict the Presence of Variant Histology?

Considering the divergent biological behaviors of certain histological subtypes of urothelial carcinoma, it would be of great importance to examine the impact of variant histology and to predict its presence in patients with bladder cancer. A single-center cohort study included 459 patients who underwent radical cystectomy for urothelial carcinoma between 2017 and 2021. Patients were followed up with until July 2022. We compared clinical, laboratory, and histopathologic characteristics and the overall survival between patients with pure urothelial carcinoma and variant histologies. Our results showed that the patients with variant histology were older and preoperatively more frequently had hydronephrosis and higher values of leukocytes and neutrophils. Also, we found a significant association between variant histology and an advanced stage of tumor disease, the presence of lymphovascular invasion, positive surgical margins, and metastases in surgically resected lymph nodes. The number of neutrophils was identified as an independent preoperative predictor of the presence of variant histology after a radical cystectomy. The overall survival of the patients with variant histology was significantly lower compared to the patients with pure urothelial carcinoma. According to our results, the presence of variant histology represents a more aggressive form of the disease. Preoperative neutrophil counts may indicate the presence of variant histology of urothelial carcinoma in patients with bladder cancer.

Application of nanotechnology in bladder cancer diagnosis and therapeutic drug delivery

Bladder cancer (BC) is one of the most common malignant tumors in the urinary system, and its high recurrence rate is a great economic burden to patients. Traditional diagnosis and treatment methods have the disadvantages of insufficient targeting, obvious side effects and low sensitivity, which seriously limit the accurate diagnosis and efficient treatment of BC. Due to their small size, easy surface modification, optical properties such as plasmon resonance, and surface enhanced Raman scattering, good electrical conductivity and photothermal conversion properties, nanomaterials have great potential application value in the realization of specific diagnosis and targeted therapy of BC. At present, the application of nanomaterials in the diagnosis and treatment of BC is attracting great attention and achieving rich research results. Therefore, this paper summarizes the recent research on nanomaterials in the diagnosis and treatment of BC, clarifies the existing advantages and disadvantages, and provides theoretical guidance for promoting the accurate diagnosis and efficient treatment of BC.

Sarcomatoid Urothelial Carcinoma Is Associated With Limited Response to Neoadjuvant Chemotherapy and Poor Oncologic Outcomes After Radical Cystectomy

INTRODUCTION

To examine oncologic outcomes and response to neoadjuvant chemotherapy (NAC) in patients with sarcomatoid urothelial carcinoma (SUC) treated with radical cystectomy (RC).

MATERIALS AND METHODS

We retrospectively queried our institutional database (2003-18) and Surveillance, Epidemiology, and End Results (SEER)-Medicare (2004-2015) for patients with cT2-4, N0-2, M0 SUC and conventional UC (CUC) treated with RC. Clinicopathologic characteristics were described using descriptive statistics (t test, χ2-test and log-rank-test for group comparison). Overall (OS) and recurrence-free-survival (RFS) after RC were estimated with the Kaplan Meier method and associations with OS were evaluated with Cox proportional hazards models.

RESULTS

We identified 38 patients with SUC and 287 patients with CUC in our database, and 190 patients with SUC in SEER-Medicare. In the institutional cohort, patients with SUC versus CUC had higher rates of pT3/4 stage (66% vs. 35%, P < 0.001), lower rates of ypT0N0 (6% vs. 35%, P = .02), and worse median OS (17.5 vs. 120 months, P < .001). Further, patients with SUC in the institutional versus SEER-Medicare cohort had similar median OS (17.5 vs. 21 months). In both cohorts, OS was comparable between patients with SUC undergoing NAC+RC vs. RC alone (17.5 vs. 18.4 months, P = .98, institutional cohort; 24 vs. 20 months, P = .56, SEER cohort). In Cox proportional hazards models for the institutional RC cohort, SUC was independently associated with worse OS (HR 2.3, CI 1.4-3.8, P = .001).

CONCLUSION

SUC demonstrates poor pathologic response to NAC and worse OS compared with CUC, with no OS benefit associated with NAC. A unique pattern of rapid abdominopelvic cystic recurrence was identified.

A proof-of-concept study on endoscopic ultrasound-guided biopsy of detrusor muscle in porcine bladders

Introduction

Conventionally, we rely on transurethral resection of bladder tumour (TURBT) for local staging of muscle-invasive bladder cancer (MIBC). However, the procedure is limited by its staging inaccuracy which may delay the definitive treatment of MIBC.

Methods

We conducted a proof-of concept study on endoscopic ultrasound (EUS)-guided biopsy of detrusor muscle in porcine bladders. Five porcine bladders were used in this experiment. Upon EUS, four layers of tissue including the mucosa (hypoechoic), submucosa (hyperechoic), detrusor muscle (hypoechoic) and serosa (hyperechoic) could be identified.

Results

A total of 37 EUS-guided biopsies were taken from 15 sites (three sites per bladder), and the mean number of biopsies taken from each site was 2.47±0.64. Among the 37 biopsies, 30 of them (81.1%) obtained detrusor muscle in the biopsy specimen. For the per biopsy site analysis, detrusor muscle was obtained in 73.3% if only one biopsy was taken, and 100% if two or more biopsies were taken from the same biopsy site. Overall, detrusor muscle was successfully obtained from all 15 biopsy sites (100%). No bladder perforation was observed throughout all biopsy processes.

Conclusion

EUS-guided biopsy of the detrusor muscle could be performed during the initial cystoscopy session, thus expediting the histological diagnosis and subsequent treatment of MIBC.

Sarcomatoid urothelial carcinoma of the renal pelvis treated with immunotherapy

BACKGROUND

Sarcomatoid carcinoma is a rare, high-grade malignancy with epithelial and mesenchymal components. It may be a good candidate for immunotherapy because it is associated with overexpression of programmed cell death ligand 1. Sarcomatoid urothelial carcinoma (UC) of the upper urinary tract is extremely rare. Here we report the first case of sarcomatoid UC of the renal pelvis that responded to immunotherapy.

CASE PRESENTATION

A 79-year-old man was referred to our hospital complaining of various symptoms, including anorexia and abdominal pain. A computed tomography scan revealed a right atrial tumor, a 9 cm left renal mass with a renal vein tumor thrombus, para-aortic lymphadenopathy, and multiple small lung nodules. The patient underwent resection of the right atrial tumor. Pathological analysis of the tumor did not lead to an accurate diagnosis even after several rounds of immunohistochemistry. He underwent a needle biopsy of the left kidney and was initially diagnosed with collecting duct carcinoma, a rare subtype of renal cell carcinoma (RCC). Following the initial diagnosis, immunotherapy with nivolumab and ipilimumab commenced. Thereafter, almost all lesions, including the left renal tumor, were reduced in size. However, he underwent a left nephrectomy approximately a year after beginning immunotherapy due to repeated left renal bleeding. Histological examination of the nephrectomy specimen revealed two forms of cancer-sarcomatoid UC and conventional high-grade UC. Two months after surgery, the patient was found to have new lung metastases. He underwent chemotherapy with gemcitabine and cisplatin, followed by immunotherapy with pembrolizumab. However, both treatments were ineffective. The patient died of cancer 19 months after his first admission.

CONCLUSIONS

The presented case of sarcomatoid UC of the renal pelvis that partially responded to immunotherapy suggests that immunotherapy can be a promising treatment for sarcomatoid UC.

Conditional survival after radical cystectomy for non-metastatic muscle-invasive squamous cell carcinoma of the urinary bladder: A population-based analysis

PURPOSE

To assess the effect of event-free survival duration on cancer-specific mortality (CSM) after radical cystectomy (RC) in nonmetastatic muscle-invasive squamous cell carcinoma of the urinary bladder.

METHODS

RC patients treated for non-metastatic muscle-invasive squamous cell carcinoma of the urinary bladder were identified within the Surveillance, Epidemiology, and End Results database (2000-2018). Independent predictor status for CSM of T and N stage groupings (i.e., T2N0, T3N0, T4N0, and TanyN1-3) was tested in multivariable Cox-regression models. Conditional 5-year CSM-free estimates were assessed at baseline and at 4 specific event-free survival times (i.e. 6, 12, 18 and 24 months), within each of the 4 examined stage groups.

RESULTS

Of 981 RC patients, 206 (21%), 416 (42%), 152 (16%), and 207 (21%) were T2N0, T3N0, T4N0, and TanyN1-3, respectively. In multivariable Cox-regression models T3N0 (HR 1.94), T4N0 (HR 5.22), and TanyN1-3 (HR 6.62) were independent predictors of CSM, relative to T2N0. In conditional survival analyses based on 24 months event-free status, survival estimates were: 89% for T2N0 vs. 76% at baseline (Δ = 13%), 84% for T3N0 vs. 58% at baseline (Δ = 26%), 69% for T4N0 vs. 25% at baseline (Δ = 44%), 69% for TanyN1-3 vs. 22% at baseline (Δ = 47%).

CONCLUSIONS

Event-free status at 24 months of follow-up is associated with substantially higher CSM-free survival than when CSM-free survival is predicted at baseline. The magnitude of this effect is most pronounced in TanyN1-3 and T4N0 patients, intermediate in T3N0 and more modest, nonetheless important, in T2N0.

Urinary Neuroendocrine Neoplasms Treated in the “Modern Era”: A Multicenter Retrospective Review

BACKGROUND

Primary urinary neuroendocrine neoplasms (U-NENs) are extremely rare thus optimal treatment is unknown. Grading and treatment are typically extrapolated from other primary sites. Since 2010, the clinical landscape for NENs has changed substantially. We performed a retrospective review of U-NENs to assess treatment patterns and oncologic outcomes of patients treated in the recent era of NEN therapy.

PATIENTS AND METHODS

A multicenter retrospective review of patients diagnosed after 2005 and alive after 2010. Time to treatment failure (TTF) was used to evaluate progression and toxicity for systemic therapy. Tumors were categorized as having either well-differentiated neuroendocrine tumor (WDNET) or poorly differentiated neuroendocrine carcinoma (PDNEC) histology.

RESULTS

A total of 134 patients from 6 centers were included in our analysis, including 94 (70%) bladder, 32 (24%) kidney, 2 (1.5%) urethra and 4 other urinary primaries (3.0%). Poorly-differentiated neuroendocrine carcinoma was more common in bladder (92%) than non-bladder tumors (8%). Median Ki-67 available in bladder primary was 90% (n = 24), kidney 10% (n = 23), ureter 95% (n = 1), urethra 54% (n = 2), and others 90% (n = 3). Patients received a median of 2 therapies (range 0-10). Median time to death was not reached in locoregional WDNETs versus 8.2 years (95% CI, 3.5-noncalculable) in metastatic WDNETs (predominantly renal primary). Median time to death was 3.6 years (95% CI, 2.2-9.2) in locoregional PDNECs versus 1 year (95% CI, 0.8-1.3) in metastatic PDNECs (predominantly bladder primary).

CONCLUSION

This is the most extensive series examining treatment patterns in patients with U-NENs in the recent era of NEN therapy. The apparent inferior survival for bladder NENs is likely due to the preponderance of PDNECs in this group. As predicted, treatments for U-NENs mirrored that of other more common NENs. In our retrospective cohort, we observed that patients with WD-UNETs treated with peptide receptor radionuclide therapy (PRRT) and everolimus suggested potential activity for disease control in WD-UNETs. Prospective studies are needed to assess the activity of new oncology drugs in UNENs.

Prognostic value of the sarcomatoid component in bladder cancer: A propensity score matching study

Sarcomatoid carcinoma of the bladder is rare, and little is known about the prognostic impact of the proportion of sarcomatoid components of the bladder. The present study aimed to assess the prognostic value of the proportion of sarcomatoid components with regard to death and recurrence rates in patients with bladder cancer (BC), and to validate the worse survival results of sarcomatoid carcinomas of the bladder using propensity score matching. Patients with sarcomatoid carcinoma of the bladder who were treated at the Affiliated Hospital of Qingdao University between August 2010 and May 2021 were included in the study. A 1:2 propensity score matching system based on age, sex and pathological T stage was used for sarcomatoid and non-sarcomatoid carcinoma matching. Finally, 114 patients with BC were included. Patients with sarcomatoid carcinoma had worse 5-year cancer-specific survival (CSS) (69.1 vs. 86.9%; log-rank P=0.008) and recurrence-free survival (RFS) (64.1 vs. 83.6%; log-rank P=0.001) rates compared with patients with non-sarcomatoid carcinoma, as had the subgroup with muscle invasion. Multivariate analysis revealed sarcomatoid carcinoma as an independent prognostic factor. Patients with a low proportion of sarcomatoid components (1-50%) had a better prognosis than patients with a high proportion (>50%), and no significant difference was found compared with the non-sarcomatoid group. Overall, a proportion of sarcomatoid components >50% was a predictor of CSS and RFS. Sarcomatoid components markedly increased the risk of death and recurrence in muscle-invasive BC, but not in non-muscle-invasive BC. A higher proportion of sarcomatoid components was significantly associated with poorer survival.

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.

Histological variants and lymphovascular invasion in upper tract urothelial carcinoma can stratify prognosis after radical nephroureterectomy

OBJECTIVES

Patients with histological variants (HV) of bladder cancer have more advanced disease and poorer survival rates than those with pure urothelial carcinoma (UC). Moreover, lymphovascular invasion (LVI) is an important biomarker after RNU in systematic reviews and meta-analyses. Thus, here we investigated the clinical and prognostic impact of HV and LVI in patients with upper tract urothelial carcinoma (UTUC) treated with radical nephroureterectomy (RNU).

METHODS

Data from 223 UTUC patients treated with RNU without neoadjuvant chemotherapy were retrospectively evaluated. We analyzed differences in clinicopathological features and survival rates between patients with pure UC and those with HV. Conditional survival (CS) analysis was performed to obtain prognostic information over time.

RESULTS

A total of 32 patients (14.3%) had HV, with the most common variant being squamous differentiation, followed by glandular differentiation. UTUC with HV was significantly associated with advanced pathological T stage (pT ≥ 3), higher tumor grade (G3), and LVI, compared to pure UC (all P < 0.01). Progression-free survival (PFS), cancer-specific survival (CSS), and overall survival (OS), were all significantly worse in the HV group compared to the pure UC group (all, P < 0.001). In multivariable analysis, HV and LVI were independent predictors of CSS and OS. We classified the patients into three groups using these two predictors: low-risk (neither HV nor LVI), intermediate-risk (either HV or LVI), and high-risk (both HV and LVI). Significant differences in PFS, CSS, and OS rates were found among the 3 groups. In CS analysis, the conditional PFS, CSS, and OS rates at 1, 2, 3, 4, and 5 years improved with increased duration of event-free survival. CS analysis revealed that most progression events occurred within 2 years after RNU, and patients with risk factors had worse PFS at all time points.

CONCLUSIONS

A risk model using HV and LVI can stratify PFS, CSS, and OS of patients treated with RNU. In addition, CS analysis revealed that HV and LVI were poor prognostic factors over time after RNU.

Differences in Cancer-Specific Mortality after Trimodal Therapy for T2N0M0 Bladder Cancer according to Histological Subtype

We aimed at assessing the impact of non-urothelial variant histology (VH), relative to urothelial carcinoma of the urinary bladder (UCUB), on cancer-specific mortality (CSM) in T2N0M0 bladder cancer patients treated with trimodal therapy (TMT). TMT patients treated for T2N0M0 bladder cancer were identified within the Surveillance, Epidemiology, and End Results database (2000−2018). Patients who underwent TMT received trans-urethral resection of the bladder tumor, chemotherapy, and radiotherapy. CSM-FS rates were tested using Kaplan−Meier plots and multivariable Cox-regression (MCR) models according to histological subtype: UCUB vs. neuroendocrine carcinoma vs. squamous cell carcinoma vs. adenocarcinoma. A total of 3846 T2N0MO bladder cancer patients treated with TMT were identified. Of these, 3627 (94.3%) harbored UCUB, while 105 (2.7%), 85 (2.2%), and 29 (0.8%) harbored neuroendocrine carcinoma, squamous cell carcinoma, and adenocarcinoma, respectively. In Kaplan−Meier analyses, 3-yr CSM-FS rates were 57% for UCUB, 51% for neuroendocrine carcinoma, 35% for squamous cell carcinoma, and 60% for adenocarcinoma (p-value < 0.0001). In MCR models, only squamous cell carcinoma exhibited higher CSM than UCUB (HR 1.98, 95%CI 1.5−2.61, p-value < 0.001). Despite the small number of observations, squamous cell carcinoma distinguished itself from UCUB based on worse survival in T2N0M0 patients after TMT.

Bladder Urothelial Carcinoma: Machine Learning-based Computed Tomography Radiomics for Prediction of Histological Variant

RATIONALE AND OBJECTIVES

Histological variant (HV) of bladder urothelial carcinoma (UC) is a significant factor for therapy management. We aim to assess the predictive performance of machine learning (ML)-based Computed Tomography radiomics of UC for HV.

MATERIALS AND METHODS

Volume of interest of 37 bladder UC tumors, of which 21 were pure and 16 were HV, were manually segmented. The extracted first- and second-order texture features (n = 117) using 3-D Slicer radiomics were compared to the radical cystectomy histopathological results. ML algorithms were performed to determine the significant models using Python 2.3, Pycaret library. The sample size was increased to 74 by synthetic data generation, and three outliers from the training set were removed (training dataset; n = 52, test dataset; n = 19). The predictive performances of 15 ML algorithms were compared. Then, the best two models were evaluated on the test set and ensembled by Voting Classifier.

RESULTS

The ML algorithms demonstrated area under curve (AUC) and accuracy ranging 0.79-0.97 and 50%-90%, respectively on the train set. The best models were Gradient Boosting Classifier (AUC: 0.95, accuracy: 90%) and CatBoost Classifier (AUC: 0.97, accuracy: 85%). On the test set; the Voting Classifier of these two models demonstrated AUC, accuracy, recall, precision, and F1 scores as follows; 0.93, 79%, 86%, 67%, and 75%, respectively.

CONCLUSION

ML-based Computed Tomography radiomics of UC can predict HV, a prognostic factor that is indeterminable by qualitative radiological evaluation and can be missed in the preoperative histopathological specimens.

Radical cystectomy for bladder urothelial carcinoma with aggressive variant histology

Purpose: The aim of this study is to report our experience in managing bladder cancer in patients with variant pathology. Methods: Retrospective data collection for all patients managed by radical cystectomy over the last 3 years for a variant pathol-ogy was completed. We specifically included micropapillary and nested variants. Results: Ten patients were identified, with eight having micropapillary carcinoma (MPC) and two having nested vari-ants. Nine patients were male. The median age was 75. The two patients with nested variant were 56 and 62 years old, respec-tively, whereas all patients with MPC were over the age of 70. Upon cystectomy of all micropapillary cases, three patients(37.5%) had positive lymph node invasion and the final patholo-gy was T2 (two patients), T3 (two patients), and T4 (four patients). Barring a grade III complication Clavien-Dindo classi-fication due to wound dehiscence that necessitated secondary surgical closure, there were no specific perioperative complica-tions. Given the urethral invasion, cystourethrectomy was per-formed on the female patient. Within a median 13-month fol-low-up, three patients developed local recurrence, including two urethral and one new lateral pelvic mass. Conclusions: Considering the muscle invasive nature of micropapillary and nested bladder cancer, aggressive surgical management should not be postponed. Moreover, due to notable prevalence of concurrent and/or recurrent urethral involvement, initial urethrectomy or early and frequent postoperative ure-throscopy should be provided. Patients with variant histology bladder cancer may benefit from early radical cystectomy when compared to bladder sparing protocols and prostate sparing cystectomy treatment options. 

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.

Prognostic Factors of Survival for High-Grade Neuroendocrine Neoplasia of the Bladder: A SEER Database Analysis

Background: High-grade neuroendocrine carcinoma (NEC) is a rare and aggressive variant of bladder cancer. Considering its rarity, its therapeutic management is challenging and not standardized. Methods: We analyzed data extracted from the Surveillance, Epidemiology, and End Results (SEER) registry to evaluate prognostic factors for high-grade NEC of the bladder. Results: We extracted data on 1134 patients: 77.6% were small cell NEC, 14.6% were NEC, 5.5% were mixed neuro-endocrine non-neuroendocrine neoplasia, and 2.3% were large cell NEC. The stage at diagnosis was localized for 45% of patients, lymph nodal disease (N+M0) for 9.2% of patients, and metastatic disease for 26.1% of patients. The median overall survival (OS) was 12 months. Multivariate analysis detected that factors associated with worse OS were age being >72 years old (HR 1.94), lymph nodal involvement (HR 2.01), metastatic disease (HR 2.04), and the size of the primary tumor being >44.5 mm (HR 1.80). In the N0M0 populations, the size of the primary tumor being <44.5 mm, age being <72 years old, and major surgery were independently associated with a lower risk of death. In the N+M0 group, the size of the primary lesion was the only factor to retain an association with OS. Conclusions: Our SEER database analysis evidenced prognostic factors for high-grade NEC of the bladder that are of pivotal relevance to guide treatment and the decision-making process.

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.

Are We Ready to Implement Molecular Subtyping of Bladder Cancer in Clinical Practice? Part 2: Subtypes and Divergent Differentiation

Following several attempts to achieve a molecular stratification of bladder cancer (BC) over the last decade, a "consensus" classification has been recently developed to provide a common base for the molecular classification of bladder cancer (BC), encompassing a six-cluster scheme with distinct prognostic and predictive characteristics. In order to implement molecular subtyping (MS) as a risk stratification tool in routine practice, immunohistochemistry (IHC) has been explored as a readily accessible, relatively inexpensive, standardized surrogate method, achieving promising results in different clinical settings. The second part of this review deals with the pathological and clinical features of the molecular clusters, both in conventional and divergent urothelial carcinoma, with a focus on the role of IHC-based subtyping.

Neoadjuvant and Adjuvant Chemotherapy for Variant Histology Bladder Cancers: A Systematic Review and Meta-Analysis

Context

To improve the prognosis of variant histology (VH) bladder cancers, clinicians have used neoadjuvant chemotherapy (NAC) or adjuvant chemotherapy (AC) on the basis of radical cystectomy (RC). Despite some new data, the evidence remains mixed on their efficacy.

Objective

To update the current evidence on the role of NAC and AC for VH bladder cancers.

Evidence Acquisition

We searched for all studies investigating NAC or AC for bladder cancer patients with variant histology in PubMed, Embase, and the Cochrane Central Register of Controlled Trials up to December 2021. The primary end points were recurrence-free survival (RFS), cancer-specific survival (CSS), and overall survival (OS).

Evidence Synthesis

We identified 18 reports comprising a total of 10,192 patients in the NAC studies. In patients with VH, the use of NAC did improve CSS (hazard ratio [HR] 0.74, 95% confidence interval [CI] 0.55–0.99, p = 0.044), and OS (HR 0.74, 95% CI 0.66–0.84, p = 0.000), but not RFS (HR 1.15, 95% CI 0.56–2.33, p = 0.706). Subgroup analyses demonstrated that receiving NAC was associated with better OS in sarcomatoid VH (HR 0.67, 95% CI 0.54–0.83, p = 0.000) and neuroendocrine VH (HR 0.54, 95% CI 0.43–0.68, p = 0.000). For AC, we identified eight reports comprising a total of 3254 patients. There was a benefit in CSS (HR 0.61, 95% CI 0.43–0.87, p = 0.006) and OS (HR 0.76, 95% CI 0.60–0.98, p = 0.032). Subgroup analyses demonstrated that only neuroendocrine VH had better CSS (HR 0.29, 95% CI 0.13–0.67, p = 0.174) when receiving AC.

Conclusions

NAC or AC for VH bladder cancers confers an OS and CSS benefit compared with RC alone. For NAC, the benefit was independently observed in the sarcomatoid and neuroendocrine subgroups. As for AC, only neuroendocrine subgroups improved CSS.

Systematic Review Registration

https://www.crd.york.ac.uk/prospero/, identifier CRD42021289487.

Variant histologies of urothelial carcinoma: Does it change the survival outcomes in patients managed with radical cystectomy?

OBJECTIVE

To investigate the impact of variant histologies (VH) of urothelial carcinoma (UC) on survival outcomes after radical cystectomy (RC).

MATERIALS AND METHODS

Data from 181 patients with UC treated with RC between January 2013 and December 2019 at a single tertiary care referral center were retrospectively accessed. All RC specimens were assigned by genitourinary dedicated pathologists. Overall survival (OS), disease-specific survival (DSS) and recurrence-free survival (RFS) were evaluated using the Kaplan-Meier methodology and the Cox proportional hazards regression.

RESULTS

Of 181 patients, 43.1% (n = 78) had VH, with the most common being squamous differentiation (n = 29), followed by mixed variants (n = 18), micropapillary variant (n = 10) and other subtypes (n = 21). The median (range) follow-up was 35 (18-59) months. Kaplan-Meier survival analysis shows that median OS and DS were significantly worse for VH patients (78 vs 31 months, p = 0.038; not reached vs 42 months; p = 0.016). At 5 years, VH was associated with a 12% and 14% decrease in OS and DSS, respectively. No significant statistical difference between the two groups was reached regarding RFS. However, after adjusting for confounders, such as, demographics characteristics, comorbidities and pathological features, VH were not associated with any survival outcomes.

CONCLUSIONS

Our study evidenced the high incidence of bladder cancers with VH. Although clearly associated with features of more aggressive behavior, VH had not any significant impact in survival expectancies when all confounders are adjusted in multivariate analyses.

Clinical and Genomic Characterization of Bladder Carcinomas With Glandular Phenotype

PURPOSE

To compare oncologic outcomes and genomic alteration profiles in patients with bladder and urachal adenocarcinoma, urothelial carcinoma (UC) with glandular differentiation, and UC, not otherwise specified (NOS) undergoing surgical resection, with emphasis on response to systemic therapy.

METHODS

We identified patients with bladder cancer with glandular variants who underwent surgical resection at Memorial Sloan Kettering from 1995 to 2018 (surgical cohort) and/or patients who had tumor sequencing using a targeted next-generation sequencing platform (genomics cohort). Pathologic complete and partial response rates to neoadjuvant chemotherapy (NAC) and recurrence-free and cancer-specific survival were measured. Alteration frequencies between histologic subtypes were compared.

RESULTS

Thirty-seven patients with bladder adenocarcinoma, 46 with urachal adenocarcinoma, 84 with UC with glandular differentiation, and 1,049 with UC, NOS comprised the surgical cohort. Despite more advanced disease in patients with bladder and urachal adenocarcinoma, no significant differences in recurrence or cancer-specific survival by histology were observed after adjusting for stage. In patients with UC with glandular differentiation, NAC resulted in partial (≤ pT1N0) and complete (pT0N0) responses in 28% and 17%, respectively. Bladder and urachal adenocarcinoma genomic profiles resembled colorectal adenocarcinoma with frequent TP53, KRAS, and PIK3CA alterations while the genomic profile of UC with glandular differentiation more closely resembled UC, NOS. Limitations include retrospective nature of analysis and small numbers of nonurothelial histology specimens.

CONCLUSION

The genomic profile of bladder adenocarcinomas resembled colorectal adenocarcinomas, whereas UC with glandular differentiation more closely resembled UC, NOS. Differences in outcomes among patients with glandular bladder cancer variants undergoing surgical resection were largely driven by differences in stage. Cisplatin-based NAC demonstrated activity in UC with glandular differentiation, suggesting NAC should be considered for this histologic variant.

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.

Accuracy and prognostic value of radiological lymph node features in variant histologies of bladder cancer

Purpose

To provide first evidence of lymph node (LN) staging using CT scan and its prognostic value in variant histologies of bladder cancer. This knowledge may optimize patient management with variant histologies based on CT morphological findings.

Methods

Preoperative CT scans of patients with variant histologies who underwent RC between 2004 and 2019 were reanalyzed by two independent radiologists in a blinded review process. Specificity, sensitivity, and accuracy for LN staging as well as LN characteristics were evaluated. Correlation with survival was investigated by Kaplan–Meier method, log-rank test and multivariate analysis.

Results

1361 patients with primary tumor of the bladder underwent RC, of which 163 (12%) patients revealed variant histologies. 65 (47.8%) patients have shown an urothelial variant (UV) and 71 (52.2%) a non-urothelial variant (NUV). LN metastases were found in 18 (27.7%) patients with UV and 21 (29.6%) patients with NUV. The accuracy to detect LN metastasis for all variant histologies was 62% with a sensitivity of 46% and a specificity of 70%. Subgroups of UV and NUV revealed an accuracy of 67% and 57%. An increased number of regional LN (HR 2.8; 1.34–6.18) and the loss of fatty hilum (HR 0.36, 0.17–0.76) were prognostic parameters. In multivariate analysis, a fatty hilum (HR 0.313, 0.104–0.945) and the presence of lymph node metastases (HR 2.866, 1.140–7.207) were prognostic.

Conclusion

This first study on CT morphological behavior of variant histologies revealed an accuracy of UV and NUV comparable to UC with low specificity for all variant histologies. CT scan prior RC should be interpreted in regard to histological subtypes.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00345-022-04010-6.

Impact of Adjuvant Chemotherapy on Variant Histology of Upper Tract Urothelial Carcinoma: A Propensity Score-Matched Cohort Analysis

Background

The advantage of adjuvant chemotherapy for upper urinary tract urothelial cancer (UTUC) has been reported, whereas its impact on upper tract cancer with variant histology remains unclear. We aimed to answer the abovementioned question with our real-world data.

Design, Setting, and Participants

Patients who underwent radical nephroureterectomy (RNU) and were confirmed to have variant UTUC were retrospectively evaluated for eligibility of analysis. In the Taiwan UTUC Collaboration database, we identified 245 patients with variant UTUC among 3,109 patients with UTUC who underwent RNU after excluding patients with missing clinicopathological information.

Intervention

Those patients with variant UTUC were grouped based on their history of receiving adjuvant chemotherapy or not.

Outcome Measurements and Statistical Analysis

Propensity score matching was used to reduce the treatment assignment bias. Multivariable Cox regression model was used for the analysis of overall, cancer-specific, and disease-free survival.

Results and Limitations

For the patients with variant UTUC who underwent adjuvant chemotherapy compared with those without chemotherapy, survival benefit was identified in overall survival in univariate analysis (hazard ratio (HR), 0.527; 95% confidence interval (CI), 0.285–0.973; p = 0.041). In addition, in multivariate analysis, patients with adjuvant chemotherapy demonstrated significant survival benefits in cancer-specific survival (OS; HR, 0.454; CI, 0.208–0.988; p = 0.047), and disease-free survival (DFS; HR, 0.324; 95% CI, 0.155–0.677; (p = 0.003). The main limitations of the current study were its retrospective design and limited case number.

Conclusions

Adjuvant chemotherapy following RNU significantly improved cancer-related survivals in patients with UTUC with variant histology.

Molecular Subtypes as a Basis for Stratified Use of Neoadjuvant Chemotherapy for Muscle-Invasive Bladder Cancer—A Narrative Review

Simple Summary

Although it is one disease, cancer of the urinary bladder occurs in several molecular subtypes that can be identified by laboratory tests. Tumors of advanced stages are treated with surgical removal of the urinary bladder with or without addition of chemotherapy. About 50% of patients are cured by surgery and this proportion is increased slightly by the addition of chemotherapy. Still, many patients do not benefit from chemotherapy, which also comes with significant toxicity. Recent advances in the field suggest that molecular subtypes can help identify patient categories that do or do not benefit from adding chemotherapy to surgery. In this article, we review the literature and conclude that molecular subtypes are likely to have such a role in the future but that there are differences between studies that make them challenging to compare. The current evidence is insufficient to guide clinical practice.

Abstract

There are no established biomarkers to guide patient selection for neoadjuvant chemotherapy prior to radical cystectomy for muscle-invasive bladder cancer. Recent studies suggest that molecular subtype classification holds promise for predicting chemotherapy response and/or survival benefit in this setting. Here, we summarize and discuss the scientific literature examining transcriptomic or panel-based molecular subtyping applied to neoadjuvant chemotherapy-treated patient cohorts. We find that there is not sufficient evidence to conclude that the basal subtype of muscle-invasive bladder cancer responds well to chemotherapy, since only a minority of studies support this conclusion. More evidence indicates that luminal-like subtypes may have the most improved outcomes after neoadjuvant chemotherapy. There are also conflicting data concerning the association between biopsy stromal content and response. Subtypes indicative of high stromal infiltration responded well in some studies and poorly in others. Uncertainties when interpreting the current literature include a lack of reporting both response and survival outcomes and the inherent risk of bias in retrospective study designs. Taken together, available studies suggest a role for molecular subtyping in stratifying patients for receiving neoadjuvant chemotherapy. The precise classification system that best captures such a predictive effect, and the exact subtypes for which other treatment options are more beneficial remains to be established, preferably in prospective studies.

A Personalized Approach to Radical Cystectomy Can Decrease Its Complication Rates

The aim of this study was to assess the influence of a patient’s general status on perioperative morbidity and mortality after radical cystectomy, and to assess which of the used scales is best for the prediction of major complications. The data of 331 patients with muscle-invasive bladder cancer, who underwent radical cystectomy, were analyzed. The general status was assessed according to the American Society of Anesthesiologists (ASA), Charlson Comorbidity Index (CCI), Eastern Cooperative Oncology Group (ECOG), and Geriatric-8 (G-8) scales. Complications were classified according to the Clavien–Dindo classification system. In a group of patients with the highest complication rate according to the Clavien–Dindo scale, (i) statistically more patients rated high according to the ASA and ECOG scales, (ii) patients had significantly higher CCI scores (minor complications (I-II), and (iii) there were significantly more patients rated as frail with G8—predominantly those with 11 points or fewer in the scale. A patient’s general status should be assessed before the start of therapy because patients with a high risk of death or serious complications (evaluated with any rating scale) should be offered conservative treatment. None of the scales can describe the risk of cystectomy, because the percentage of patients with major complications among those who achieved worse score results on any scale was not significantly different from the percentage of patients with major complications in the general group.

The Accuracy of Transurethral Bladder Resection in Detecting Bladder Cancer Histological Variants and Their Prognostic Value at Radical Cystectomy

Objectives: to investigate the accuracy of transurethral resection of bladder tumours (TURBT) in detecting histological variants (BHV) at radical cystectomy (RC) and to evaluate the impact of TURBT before cystectomy on oncological outcomes. Methods: Data of 410 consecutive RCs were assessed. Positive and negative predictive values were used to assess the accuracy of TURBT in detecting BHV. Cohen’s Kappa coefficient was used to calculate the agreement grade. Logistic regression analysis predicted features based on the presence of BHV at TURBT. Multivariable backward conditional Cox regression analysis was used to estimate oncological outcomes. Results: A total of 73 patients (17.8%) showed BHV at TURBT as compared to 108 (26.3%) at RC. A moderate agreement in histological diagnosis was found between TURBT and RC (0.58). However, sensitivity and specificity in detecting BHV were 56% and 96%, respectively. Furthermore, positive predictive value (PPV) was 84.7% and negative predictive value (NPV) was 84.6%. Presence of BHV at TURBT was an independent predictor for pathologic upstage, albeit not a predictor for positive nodes or positive surgical margins. However, at multivariable analysis adjusted for all confounders, presence of BHV at TURBT was an independent predictor for recurrence after RC, but not for survival. Conversely, the presence of BHV at RC was an independent predictor for both recurrence and survival. Conclusion: There was a moderate agreement between TURBT and RC histopathological findings. TURBT, alone, could not provide an accurate and definitive histological diagnosis. Detection of BHV in TURBT specimens is not an independent predictor of oncological outcomes; indeed, only pathological features at RC are associated with worse survival. However, BHV presence in cystectomy specimens resulted as an independent predictor of both cancer-specific and overall mortality.

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.

Prediction of pathological response following neoadjuvant chemotherapy in patients with muscle-invasive bladder cancer: the PRE-PREVENCYS trial

Background

The recommended treatment for patients with non-metastatic muscle-invasive bladder cancer (MIBC) is neoadjuvant chemotherapy (NAC) and radical cystectomy (RC). Following NAC, 20–40% of patients experience a complete pathological response (pCR) in the RC specimen and these patients have excellent long-term overall survival. Subject to debate is, however, whether patients with a pCR to NAC benefit from RC, which is a major surgical procedure with substantial morbidity, and if these patients might be candidates for close surveillance instead. However, currently it is not possible to accurately identify patients with a pCR to NAC in whom RC might be withheld. The objective of this study is to assess whether pathological response in the RC specimen after NAC can be predicted based on clinical, radiological, and histological variables and on a wide set of molecular biomarkers assessed in tissue, blood and urine.

Methods

This is a multicentre, prospective cohort study, including patients with cT2a-T4a N0-N1 M0 urothelial cell MIBC who are scheduled to undergo cisplatin-based NAC followed by RC. Prior to start of therapy, a 2-Deoxy-2-[18F] fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography/computed tomography (PET/CT) is performed. Response to NAC is evaluated by CT-scan. Blood and urine, including cytology, are prospectively collected for biomarker analyses before and after NAC. Immediately before RC, participants undergo cystoscopy with bimanual examination and a re-staging transurethral resection (TUR) of all visible cancerous lesions or with biopsies from scar tissue. Subsequently, RC is performed in all patients. Tissue from the diagnostic TUR, the re-staging TUR, and the RC specimen is examined for the presence of urothelial cancer carcinoma and DNA and RNA is isolated for molecular analysis. The primary endpoint is the pathological stage (ypTN) in the RC and ePLND specimen and its association with clinical response.

Discussion

If the PRE-PREVENCYS trial shows that the absence of residual disease after NAC in patients with MIBC is accurately predicted, a randomized controlled trial is scheduled comparing the overall survival of NAC plus RC versus NAC followed by close surveillance for patients with a clinically complete response (PREVENCYS trial).

Trial registration

Netherlands Trial Register: NL8678; Registered 20 May 2020 https://www.trialregister.nl/trial/8678

Evaluation of Therapeutic Targets in Histological Subtypes of Bladder Cancer

Histologically, bladder cancer is a heterogeneous group comprising urothelial carcinoma (UC), squamous cell carcinoma, adenocarcinomas (ACs), urachal carcinomas (UrCs), and small cell neuroendocrine carcinomas (SCCs). However, all bladder cancers have been treated so far uniformly, and targeted therapy options are still limited. Thus, we aimed to determine the protein expression/molecular status of commonly used cancer targets (programmed cell death 1 ligand 1 (PD-L1), mismatch repair (MMR), androgen and estrogen receptors (AR/ER), Nectin-4, tumor-associated calcium signal transducer 2 (Tacstd2, Trop-2), epidermal growth factor receptor (EGFR), human epidermal growth factor receptor 2 (HER2), and fibroblast growth factor receptor 3 (FGFR3)) to give first insights into whether patients with SCC, AC/UrCs, and squamous-differentiated carcinomas (Sq-BLCA) of the bladder could be eligible for targeted therapies. In addition, for MMR-deficient tumors, microsatellite instability was analyzed. We completed our own data with molecular data from The Cancer Genome Atlas (TCGA). We present ratios for each drug and cumulative ratios for multiple therapeutic options for each nonurothelial subtype. For example, 58.9% of SCC patients, 33.5% of AC/UrCs patients, and 79.3% of Sq-BLCA patients would be eligible for at least one of the analyzed targets. In conclusion, our findings hold promise for targeted therapeutic approaches in selected patients in the future, as various drugs could be applied according to the biomarker status.

Association Between Surgical Volume and Survival Among Patients With Variant Histologies of Bladder Cancer

OBJECTIVE

To examine the relationship between hospital volume and the management of bladder cancer variant histology. Variant histologies of bladder cancer are rare which limits the ability for providers to develop expertise however there is a clear hospital and/or surgeon-volume relationship for management of rare or complex surgical and/or medical diseases.

METHODS

We queried the National Cancer Database from 2004-2016 for all cases of bladder cancer, identifying cases of variant histology. Our primary outcome was overall survival while secondary outcomes included identifying treatment patterns. Hospitals were stratified into those that managed ≤2, >2-4, >4-6, and ≥6 cases per year of variant histology.

RESULTS

We identified 23,284 patients with bladder cancer of variant histology who were treated at 1301 hospitals. Few institutions had high volume experience with this disease: 18.5% (n = 241) treated >2 patients annually and 5.7% (n = 76) treated >4 cases annually. Hospital volume positively correlated with utilization of early radical cystectomy (RC) in non-muscle invasive disease and neoadjuvant chemotherapy in muscle-invasive disease. On multivariable analysis, increased hospital volume was associated with improved survival. After stratifying by sub-type, hospital volume continued to be associated with improved survival for squamous, small cell, and sarcomatoid cancers.

CONCLUSION

Management of variant histology urothelial carcinoma at high-volume centers is associated with improved overall survival. The mechanisms of this are multifactorial, and future research should focus on improvement opportunities for low-volume hospitals, centralization of care, and/or increased access to care at high-volume centers.

Setting standards for cystectomy using the British Association of Urological Surgeons Complex Operations Reports, 2016–2018

Objective:

To produce comprehensive standards for cystectomy using contemporary data collected across a nation.

Patients and methods:

Surgical departments upload cystectomy data to the British Association of Urological Surgeons (BAUS) Complex Operations Database. Analysis of 2016–2018 data was performed for all recorded 5288 patients undergoing cystectomy in England. Logistic regression with general linear models was used to assess differences in patient selection between operative modalities. Analysis involved assessment of case selection, operative decisions and outcomes, case volume and pathological outcomes.

Results:

Using national Hospital Episode Statistics, the BAUS cystectomy dataset was estimated 93% complete. Median age was 70 years (interquartile range 63–75) and 75% were male. Charlson comorbidity index ⩽2 was reported in 87%. Primary treatment of muscle-invasive bladder cancer accounted for 46% of cases. Commonest preoperative disease stages were T2N0 and T1N0 (35% and 25% respectively). Robotic-assisted (RAC), laparoscopic (LC) and open cystectomy (OC) were performed in 41%, 5.5% and 54% of cases respectively. T-stage distribution differed by operative modality. Transfusion rates were 3.7% for RAC, 6.0% for LC and 18% for OC. Increasing positive surgical margin rates were observed with increasing T-stage, up to T3. The conversion-to-open rate for minimally-invasive surgery was 1.7%. Median annual centre and surgeon case volumes were highest for RAC. Median length of stay was 7, 10 and 10 days for RAC, LC and OC respectively. Postoperative histological upstaging was common (33% of cT1, 50% of cT2 cases). Lymph node positive rates were 28% for muscle-invasive bladder cancer.

Conclusion:

Analysis of this data provides understanding of ‘real-world’ cystectomy practice. Presentation of data specific to operative modality allows surgeons and centres to benchmark their respective practices. These findings offer to enhance patient and public understanding beyond that currently facilitated by publicly-facing information sources. They carry relevance by describing a near-complete and large volume of modern practice in a publicly funded healthcare system.

Level of evidence:

2b

Evaluation of the Extent of Variant Histology in Urothelial Carcinoma as a Predictive Marker of Clinical Outcomes After Radical Cystectomy

BACKGROUND/AIM

This study investigated the impact of the extent of variant histology (VH) on the prognosis of patients with bladder cancer (BC).

PATIENTS AND METHODS

We retrospectively evaluated consecutive patients with muscle-invasive BC who were treated with radical cystectomy (RC) at our institution between 2005 and 2018. Recurrence-free survival (RFS) and overall survival (OS) rates were evaluated using Kaplan-Meier analysis and Cox regression.

RESULTS

We identified 103 and 47 patients with pure urothelial carcinoma (UC) and a VH in UC, respectively. At the cutoff of 80%, univariate analysis identified significant differences in RFS (p=0.046) and OS (p=0.038) between patients with ≥80% VH (n=21) and those with <80% VH (n=26). Multivariate analysis revealed that the presence of ≥80% VH was significantly associated with RFS and OS.

CONCLUSION

The presence of ≥80% VH in UC could be an independent predictor of recurrence and mortality after RC.

Plasmacytoid urothelial carcinoma (UC) are luminal tumors with similar CD8+ Tcell density and PD-L1 protein expression on immune cells as compared to conventional UC

BACKGROUND

Plasmacytoid urothelial carcinoma (UC) is a rare pathological variant of UC with low chemotherapeutic sensitivity and dismal outcomes. The molecular and immune profiles of such tumors remain poorly investigated.

METHODS

Herein, we investigated the phenotypical features of a cohort of plasmacytoid UC (n=32) by comparison to a control group of conventional high-grade UC with matched clinicopathological characteristics (n=30). Histopathological analysis included the following antibodies: p63, GATA3, CK5/6, CK20 and HER2. In addition, the density of intra-tumor CD8⁺ lymphocytes, and PD-L1 expression in tumor (TC) and immune cells (IC) were evaluated.

RESULTS

Plasmacytoid UC expressed GATA3 (97% vs 86% P=0.18), CK20 (59% vs 36% P=0.08) markers and showed a significantly higher rate of HER2 overexpression (2+ and 3+ score: 25% vs 0%, P<0.01) compared to controls. A significantly lower expression of CK5/6 (22% vs 56%, P<0.05) and p63 (41% vs 80%, P<0.05) was observed in plasmacytoid UC compared to controls. The density of tumor-infiltrating CD8+ cells was similar between plasmacytoid and conventional UC (P=0.9). PD-L1 expression on IC was similar compared to conventional UC (P=0.3).

CONCLUSIONS

Together, our study demonstrated that plasmacytoid UC belong to the luminal subtype and display a rather inflamed microenvironment similar to conventional UC. These data support the inclusion of plasmacytoid variant of UC in clinical trials evaluating immune checkpoint inhibitors monotherapy or combination immunotherapeutic strategies.