Advanced small cell carcinoma of the bladder: clinical characteristics, treatment patterns and outcomes in 960 patients and comparison with urothelial carcinoma

Small Cell Bladder Cancer: Treatment Patterns for Local Disease and Associated Outcomes. A Retrospective Cohort Study

BACKGROUND

Small cell bladder cancer (SCBC) is a rare histologic subtype with relative paucity of data regarding treatment response and outcomes. We reviewed 2 databases to compare outcomes in patients with localized SCBC treated with cystectomy versus concurrent chemoradiotherapy (CCRT). We hypothesized that survival would be similar with these therapy approaches.

METHODS

We retrospectively reviewed our institutional and SEER-Medicare databases to identify patients with SCBC. Overall survival (OS) was determined from the date of diagnosis to last follow-up/death. For those with nonmetastatic disease, a multivariate Cox analysis was used to compare locoregional therapy with neoadjuvant chemotherapy (NAC) + cystectomy versus CCRT.

RESULTS

We identified 53 patients in our institutional database and 1166 patients in SEER-Medicare with localized SCBC. Median OS (mOS) with NAC + cystectomy was 46 months (95% CI, 21-72) and 45 months (95% CI, 0-104) in the institutional and SEER-Medicare databases, respectively, whereas mOS with CCRT was 26 months (95% CI, 5-47) and 23 months (95% CI, 18-28) in the 2 series, respectively. In multivariate analysis, NAC followed by cystectomy was associated with an approximately 30% reduction in mortality compared to CCRT in both institutional and national databases but did not reach statistical significance (Institution HR 0.71, 95% CI, 0.22-2.4, P = .58; SEER HR 0.73, 95% CI, 0.49-1.08; P = .11).

CONCLUSIONS

SCBC is very aggressive with limited survival observed in our institutional and SEER-Medicare datasets regardless of locoregional therapy used. There is an unmet need to define the optimal locoregional therapy for nonmetastatic stage and identify novel therapeutic targets.

Current Advances in the Management of Nonurothelial Subtypes of Bladder Cancer

Urothelial cancer (UC) is the most common histology seen in bladder tumors. The 2022 WHO classification of urinary tract tumors includes a list of less common subtypes (formerly known as variants) for invasive UC which are considered high-grade tumors. This review summarizes the most recent advances in the management of selected nonurothelial subtypes of bladder cancer: squamous cell carcinoma, small cell carcinoma, sarcomatoid urothelial carcinoma, micropapillary carcinoma, plasmacytoid carcinoma, adenocarcinoma, and urachal carcinoma. The role of neoadjuvant and adjuvant chemotherapy has not been well characterized for most of these histologies, and prospective data are extremely limited. Participation in clinical trials is recommended in advanced disease.

Prognostic impact of variant histology in bladder cancer: Would early and aggressive treatment shift the paradigm?

INTRODUCTION

Bladder cancer (BC) is an increasingly frequent malignancy worldwide. Several variant histologies (VH) have been described in BC with a distinct clinical behavior.

OBJECTIVES

This study aims to assess the prognostic impact of VH in BC, comparing its outcomes to pure urothelial carcinoma PUC in both non-muscle invasive (NMIBC) and muscle-invasive (MIBC) settings.

METHODS

We included patients with primary BC, comparing those with VH with those with PUC, with an age and sex-matched proportion of 1:3, considering stage at diagnosis, recurrence-free, progression-free, and overall survival (OS). A total of 616 patients were included in the study, (460 UC and 151 VH).

RESULTS

After first TURBT, MIBC was present in 99 (64.1%) of patients with VH, and 95 (20.6%) with UC (p<0.001). Concerning NMIBC, we observed higher rates of progression to MIBC amid patients with VH (p=0.009). Nodal involvement (p=0.020) and metastatic disease (p<0.001) were significantly higher within the VH group. A higher OS was observed among patients with NMIBC of PUC (p<0.001). There were no statistically significant differences of metastasis-free survival and OS between VH and UC groups within the MIBC setting.

CONCLUSION

We confirmed that VH presents a more aggressive clinical course compared to PUC. An earlier radical treatment within the NMIBC setting could increase the oncological outcomes of the VH patients.

Clinical performance and utility of a noninvasive urine-based methylation biomarker: TWIST1/Vimentin to detect urothelial carcinoma of the bladder

Traditional clinical modalities for diagnosing bladder urothelial carcinoma (BUC) remain limited due to their invasive nature, significant costs, discomfort associated with cystoscopy, and low sensitivity to urine cytology. Therefore, there is an urgent need to identify highly sensitive, specific, and noninvasive biomarkers for the early detection of this neoplasm. Hypermethylated TWIST1/Vimentin promoter may be a noninvasive biomarker using urine sample. We assessed the TWIST1/Vimentin promoter methylation status in urine samples using the Methylated Human TWIST1 and Vimentin Gene Detection Kit (Jiangsu MicroDiag Biomedicine Co., Ltd., China). The samples were collected from five groups: group 1 consisted of patients with BUC, group 2 contained other patients with urologic tumors, group 3 consisted of patients with benign diseases (e.g., urinary tract infections, lithiasis, and benign prostatic hyperplasia), Group 4 included UTUC (upper tract urothelial carcinoma) patients and group5 comprised healthy individuals. The study encompassed 77 BUC patients, and we evaluated the degree of methylation of the TWIST1/Vimentin gene in their urine samples. Notably, TWIST1/Vimentin positivity was significantly elevated in comparison to groups 2, 3 and 5 (all p < 0.001) at a rate of 77.9%, but no significant difference was observed when compared to group 4. In the relationship between TWIST1/Vimentin methylation and clinicopathological features of BC patients from our center, we found there was no significant association between TWIST1/Vimentin status and proteinuria and/or hematuria, and hypermethylation of TWIST1 / VIM genes was found in both high and low tumor grade and in both non-muscle invasive bladder cancer (stages Tis, Ta, or T1) and muscle-invasive bladder cancer (stage T2 or above). In the multivariable analysis for cancer detection, a positive TWIST1/Vimentin methylation were significantly linked to a heightened risk of BC. Moreover, TWIST1/Vimentin promoter methylation demonstrated an ability to detect BUC in urine samples with a sensitivity of 78% and a specificity of 83%. Our findings reveal that hypermethylation of the TWIST1/Vimentin promoter occurs in bladder urothelial carcinoma, and its high sensitivity and specificity suggest its potential as a screening and therapeutic biomarker for urothelial carcinoma of the bladder.

Metastatic small cell bladder cancer treated with sequential systemic therapy including pembrolizumab and amrubicin: A case report

Introduction

Small cell bladder cancer is a relatively rare tumor, representing <1% of all bladder tumors. Amrubicin monotherapy is used as second-line treatment for small cell lung cancer in Japan.

Case presentation

A 79-year-old woman presented with gross hematuria and was diagnosed with small cell bladder cancer (T2 or higher). Neoadjuvant chemotherapy with etoposide and cisplatin resulted in a partial response. Robot-assisted radical cystectomy was performed, and radical resection was achieved. As we identified metastasis in the pleura 1 year later, we administered carboplatin and etoposide, which resulted in a partial response. Although pembrolizumab was initiated as maintenance therapy, it was not effective. Amrubicin was given as third-line therapy, and stable disease was achieved without serious adverse effect for 6 months.

Conclusion

Although there is no established treatment for metastatic small cell bladder cancer, the current case report suggests the effectiveness of amrubicin in this setting.

Small-cell neuroendocrine tumor of the bladder: Unexpected long-term survival with carboplatin-etoposide therapy in a patient with metastatic stage disease

Neuroendocrine small-cell bladder cancer is an extremely rare and aggressive entity, it constitutes <1% of all bladder malignancies. The small-cell neuroendocrine histological variant has a worse prognosis than the classical subtypes. A case of a 53-year-old female consulting with gross hematuria is presented. Cystoscopy revealed a solid aspect lesion involving the posterior wall and dome that was resected. Histopathological findings showed small-cell pure variant carcinoma, high grade, with lymph, vascular, and perineural infiltration, infiltrating the muscle layer. The extension study made by hole body computed tomography scan, showed evidence of multiple lymph nodes and multiple visceral radiological involvements, with pulmonary, hepatic, and peritoneal implants. More than 10 years later, after receiving nine cycles of carboplatin-etoposide remains in complete remission and without radiological evidence of the disease. This is, to our knowledge, one of the longest disease-free survival cases in metastatic small-cell bladder cancer published nowadays.

Acute periocular haemorrhage associated with severe proptosis as a presenting sign of orbital tumours

Periocular haemorrhage without a preceding history of trauma, and in the absence of vascular malformations is rare. While acute proptosis is well described in the setting of orbital pathology, accompanying periocular haemorrhage has been rarely reported. We describe three cases with these concomitant presenting signs in orbital malignancies - metastatic small cell bladder carcinoma, haemangiopericytoma (solitary fibrous tumour) and myeloma. Clinical photographs and radiology are presented with review of the current literature. All cases had an associated rapid onset of severe proptosis and co-existing periocular bruising on the same side. The presence of ecchymosis of the eyelids in addition to proptosis without a history of trauma warrants thorough investigation to rule out underlying potential sight and life threatening illness.

Clinical characteristics and treatment outcomes of patients with small cell carcinoma of the urinary bladder

Background

Materials and methods

Results

Conclusions

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.

Treatment Outcomes for Small Cell Carcinoma of the Bladder: Results From a UK Patient Retrospective Cohort Study

PURPOSE

Small cell carcinoma of the bladder (SCCB) is rare, accounting for less than 1% of all bladder carcinomas. It is aggressive, and outcomes are poor as a result of its early metastatic spread. Owing to its rarity, there are limitations on data to propose standardized management pathways.

METHODS AND MATERIALS

We conducted a retrospective analysis of patients presenting with pure or predominant-histology SCCB to 26 institutions in the United Kingdom between 2006 and 2016. The data cutoff date was February 1, 2018. We report patient characteristics, treatment received, and subsequent clinical outcomes.

RESULTS

A total of 409 eligible patients were included. Among these, 306 (74.8%) were male, the median age was 71 years (range, 35-96 years), and 189 patients (46.2%) had pure-histology SCCB. At data cutoff, 301 patients (73.6%) had died. The median overall survival (OS) was 15.9 months (95% CI, 13.2-18.7 months). Two hundred patients (48.9%) were confirmed to have bladder-confined disease (N0, M0), with a median OS of 28.3 months (95% CI, 20.9-35.8 months), versus a median OS of 12.7 months (95% CI, 10.9-14.6 months) for the 172 patients (42.1%) with confirmed N1-3 and/or M1 disease (hazard ratio [HR], 2.03; 95% CI, 1.58-2.60; P < .001). A total of 247 patients (61.5%) received primary chemotherapy, with a median OS of 21.6 months (95% CI, 15.5-27.6 months), versus a median OS of 9.1 months (95% CI, 5.4-12.8 months) in patients who did not receive primary chemotherapy (HR, 0.46; 95% CI, 0.37-0.59; P < .001). Choice of chemotherapy agent did not alter outcomes. For those with bladder-confined disease, 61 (30.5%) underwent cystectomy, and 104 (52.0%) received radiation therapy. Survival outcomes were similar for both cystectomy and radiation therapy. Only 6 patients (1.5%) were identified as having brain metastases at any time point.

CONCLUSIONS

To our knowledge, this is the largest retrospective study of all-stage SCCB to date. Patients have a poor prognosis overall, but survival is improved in those able to receive chemotherapy and with organ-confined disease. Brain metastases are rare.

p53 Expression, Programmed Death Ligand 1, and Risk Factors in Urinary Tract Small Cell Carcinoma

Introduction: Small cell carcinoma of the urinary tract (SCCUT) is a rare finding with poor clinical course. This study sheds light on the molecular subtype and identifies risk factors in patients diagnosed with SCCUT.

Methods: Immunohistochemical expression of immunotherapy target programmed death ligand 1 (PD-L1) and luminal (GATA3), basal (p63), and p53 markers are assessed in patients diagnosed with SCCUT. Univariate analysis identified risk factors. Overall survival (OS) is computed using the Kaplan–Meier method.

Results: Tissue was available for 70.2% (33/47). All showed a high PD-L1 expression phenotype. p53 is seen in 93.9% (31/33), mostly as overexpression, GATA3 in 45.5% (15/33), and p63 in 57.6% (19/33). For the entire cohort (n = 47), 1-year survival was 59.6%, and the median OS was 17 months. Univariate analysis shows that chemotherapy [hazard ratio (HR) = 0.29, 95% confidence interval (CI) = 0.14–0.61, p = 0.001], radical surgery (HR = 0.37, 95% CI = 0.18–0.76, p = 0.007), and diagnosis of non-pure SCCUT (HR = 0.44, 95% CI = 0.22–0.86, p = 0.02) are favorable prognostic features. Metastasis had negative associations with survival (HR = 2.1, 95% CI = 1.1–4.2, p = 0.03).

Conclusions: In this series, pure and mixed SCCUT are characterized by p53 overexpression and a high PD-L1 phenotype. Histology of non-pure SCCUT is a positive prognosticator, and radical cystectomy or chemotherapy can improve OS. These findings demonstrate that SCCUT may be eligible for PD-L1 immunotherapy.

Unfavorable Cancer-specific Survival After Neoadjuvant Chemotherapy and Radical Cystectomy in Patients With Bladder Cancer and Squamous Cell Variant: A Multi-institutional Study

BACKGROUND

Nonurothelial carcinoma (UC) malignancies have traditionally been considered to have a more aggressive clinical course, and little is known about their response to neoadjuvant therapy. We examined the effect of neoadjuvant chemotherapy (NAC) on a large population of patients with bladder cancer (BCa) with different histologic variants (HVs).

PATIENTS AND METHODS

We relied on a retrospective, multicenter database of 2858 patients with BCa who had undergone radical cystectomy with or without NAC from 1990 to 2017. Pure and mixed HVs were grouped into 6 categories: squamous cell carcinoma (SCC; n = 283; 45%), other subtypes (n = 95; 15%), micropapillary (n = 85; 14%), adenocarcinoma (n = 65; 10%), small cell (n = 54; 8.6%), and sarcomatous (n = 47; 7.6%). Kaplan-Meier and Cox regression analyses were used to examine cancer-specific survival (CSS) according to the HV, using pure UC as the reference. Logistic regression models were used to examine the odds of clinical-to-pathologic downstaging after NAC according to the HV.

RESULTS

Overall, we identified 2229 cases of pure UC and 629 cases of BCa with HVs at radical cystectomy. Of the 450 NAC-treated patients, only those patients with SCC (n = 44; 9.8%) had had worse CSS (median CSS, 33 vs. 116 months; P < .001) and higher mortality rates (hazard ratio, 2.1; P = .03) compared with those with pure UC (n = 328; 72.9%). The results of the analyses were also confirmed when the pure and mixed cases were considered separately. After adjusting for NAC, only SCC showed a lower rate of clinical-to-pathologic downstaging (odds ratio, 0.4; P = .03) compared with UC.

CONCLUSIONS

SCC was the HV exhibiting the lowest effect of NAC in terms of activity and CSS. Compared with pure UC, SCC seemed to be insensitive to traditional NAC regimens.

Prognosis of early stage small cell bladder cancer is not always dismal

Background

Small cell carcinoma of the urinary bladder (SCCB) is an extremely rare malignancy which is often associated with poor survival outcome. Literature reporting such disease is scarce. There is no standardised management. This retrospective audit examines a UK Cancer Centre’s SCCB management and survival outcomes.

Methods

Histopathology database at Nottingham University Hospitals, UK, was used to identify patients diagnosed with SCCB from January 2008 to January 2016.

Results

27 patients had confirmed diagnosis of SCCB. Mean age at diagnosis was 68.7 (range 37–90). 30% of the cases had pure small cell histology, while the rest were mixed histological subtype. Of the 12 patients with early stage disease (stage I and II), three had radical cystectomy and chemotherapy, six had both radiotherapy and chemotherapy, two had either radiotherapy or chemotherapy alone, and one declined active treatment. Of the 12 patients with advanced disease (stage III and IV), four had chemotherapy alone, four had both radiotherapy and chemotherapy and four was for best supportive care. 13 out of 16 patients who had chemotherapy received combination of carboplatin and etoposide. Patients with advanced stage disease had medial survival of 9 months (95% CI 3.9 to 14.1 months). The median survival for patients with early disease was not reached. There is significant difference in survival between early and late stage disease (p value 0.008, Log rank test).

Conclusions

Our results demonstrated a reasonable survival outcome in early stage SCCB patients. Radical multimodality treatment options should not be precluded in patients with early stage SCCB.

Neuroendocrine Carcinoma of the Urinary Bladder: A Large, Retrospective Study From the French Genito-Urinary Tumor Group

BACKGROUND

Neuroendocrine carcinoma of the urinary bladder (NCUB) is rare, accounting for < 1% of bladder cancer cases, with scarce reported data available.

MATERIALS AND METHODS

We retrospectively reviewed the data from patients with NCUB treated at French institutions. The objectives were to describe the patient characteristics, treatments received, and outcomes (ie, disease-free survival [DFS], progression-free survival, overall survival [OS]) and investigate the prognostic factors.

RESULTS

From 1997 to 2017, we included 236 patients, 173 with early-stage NCUB and 63 with advanced-stage NCUB. For those with early-stage disease, the median DFS was better for the patients who had received cisplatin-based chemotherapy compared with carboplatin (hazard ratio [HR], 1.95; 95% confidence interval [CI], 1.1-3.46), with no difference found between the neoadjuvant and adjuvant settings (HR, 1.1; 95% CI, 0.61-1.97). The median OS was 36 months (95% CI, 29-43 months) for stage I and II, 26 months (95% CI, 18 months to not reached) for stage IIIA, 16 months (95% CI, 12-21 months) for stage IIIB. The HR for stage IIIB compared with stage I/II was 2.6 (95% CI, 1.5-4.4). The DFS at 6 months was associated with OS (HR, 7.8; 95% CI, 4.1-15.0). For patients with metastases at diagnosis who had received chemotherapy, the median progression-free survival was 9 months (95% CI, 8-11) for first-line cisplatin and 6 months (95% CI, 4-13 months) for carboplatin; the median OS was 13 months (95% CI, 9-15 months). A high-risk Bajorin score (HR, 11.5; 95% CI, 1.2-112.6) and the use of carboplatin (HR, 2.26; 95% CI, 1.03-4.96) were associated with worse outcomes.

CONCLUSIONS

In early-stage disease, a shorter DFS was associated with worse OS, and the use of cisplatin was associated with better OS. For the patients with metastases at diagnosis, a high-risk Bajorin score and the use of carboplatin were associated with worse outcomes.

Advanced small-cell bladder cancer into a ureterocele: A case report and literature review

Small cell bladder cancer (SCBC) is found in 0.5–1.2% of all bladder tumors. Ureteroceles are dilatation of the distal portion of an ectopic ureter, which association with tumors are rare. This article reports the first case described of an SCBC developed into a ureterocele, beyond a literature review.

Organ-preserving approach via radiotherapy for small cell carcinoma of the bladder: an analysis based on the Japanese Radiation Oncology Study Group (JROSG) survey

Small cell carcinoma of the bladder is extremely rare, accounting for <1% of all malignant tumours in the urinary tract. Thus, no standard therapy modality for this malignancy has been established. This study aimed to retrospectively analyse the clinical outcomes associated with definitive radiotherapy for small cell carcinoma of the bladder. A questionnaire-based survey of patients with pathologically proven small cell carcinoma of the bladder treated with definitive radiation therapy between 1990 and 2010 was conducted by the Japanese Radiation Oncology Study Group. The clinical records of 12 eligible patients were collected from nine institutions. The median age of the patients was 70.5 years (range: 44-87 years), and the median follow-up period was 27.3 months (range: 3.3-117.8 months). The median prescribed dose was 60 Gy (range: 50.0-61.0 Gy), and a median of 2.0 Gy (range: 1.2-2.0 Gy) was administered per fraction. Systemic chemotherapy combined with radiotherapy was performed in eight cases (66.7%). The 3- and 5-year overall survival rates were 50.0% and 33.3%, respectively. And the 3- and 5-year local control rates were 66.7% and 55.6%, respectively. Chemotherapy significantly improved overall survival and relapse-free survival (P = 0.006 and 0.001, respectively). No serious adverse events occurred in the observation period. All patients who achieved local control maintained functional bladders. In conclusion, radiotherapy is a potential local treatment option and has an important role in maintaining quality of life. Systemic chemotherapy combined with local radiotherapy seems to be effective in improving survival.

Metastatic Small Cell Carcinoma of the Urinary Bladder That Recurred in the Vagina 6 Years after Radical Cystectomy: A Case Report

Small cell carcinoma (SCC) of the urinary bladder is highly aggressive and portends a poor outcome. Herein, we report a patient with recurrent SCC of the urinary bladder who experienced an unusually long-term disease-free duration after radical cystectomy. The patient was a 60-year-old woman who had undergone transurethral resection followed by radical cystectomy for muscle-invasive bladder cancer (high-grade urothelial carcinoma with adenocarcinomatous differentiation) 6 years prior; the surgical specimen had a negative surgical margin. She was referred to our hospital because of continuous bleeding from her vagina. Magnetic resonance imaging showed a mass located at the anterior wall of her residual vagina, a biopsy of which confirmed a pathological diagnosis of adenocarcinoma. The vaginal tumor and a section of the sigmoid colon were resected en bloc and were pathologically diagnosed as adenocarcinoma and SCC. We reevaluated the initial transurethral resection specimen and found SCC with foci of adenocarcinoma concomitant with high-grade urothelial carcinoma. Local recurrence and metastasis at the pelvic bone occurred 4 months later; although radiation therapy was performed, she died of the progressive disease.

Transcriptomic and Protein Analysis of Small-cell Bladder Cancer (SCBC) Identifies Prognostic Biomarkers and DLL3 as a Relevant Therapeutic Target

PURPOSE

Transcriptomic profiling can shed light on the biology of small-cell bladder cancer (SCBC), nominating biomarkers, and novel therapeutic targets.

EXPERIMENTAL DESIGN

Sixty-three patients with SCBC had small-cell histology confirmed and quantified by a genitourinary pathologist. Gene expression profiling was performed for 39 primary tumor samples, 1 metastatic sample, and 6 adjacent normal urothelium samples (46 total) from the same cohort. Protein levels of differentially expressed therapeutic targets, DLL3 and PDL1, and also CD56 and ASCL1, were confirmed by IHC. A SCBC PDX model was utilized to assess in vivo efficacy of DLL3-targeting antibody-drug conjugate (ADC).

RESULTS

Unsupervised hierarchical clustering of 46 samples produced 4 clusters that correlated with clinical phenotypes. Patients whose tumors had the most "normal-like" pattern of gene expression had longer overall survival (OS) compared with the other 3 clusters while patients with the most "metastasis-like" pattern had the shortest OS (P = 0.047). Expression of DLL3, PDL1, ASCL1, and CD56 was confirmed by IHC in 68%, 30%, 52%, and 81% of tissue samples, respectively. In a multivariate analysis, DLL3 protein expression on >10% and CD56 expression on >30% of tumor cells were both prognostic of shorter OS (P = 0.03 each). A DLL3-targeting ADC showed durable antitumor efficacy in a SCBC PDX model.

CONCLUSIONS

Gene expression patterns in SCBC are associated with distinct clinical phenotypes ranging from more indolent to aggressive disease. Overexpression of DLL3 mRNA and protein is common in SCBC and correlates with shorter OS. A DLL3-targeted ADC demonstrated in vivo efficacy superior to chemotherapy in a PDX model of SCBC.

Molecular Subtypes of Bladder Cancer

PURPOSE OF REVIEW

Recent whole genome characterizations of primary human bladder cancers revealed that they can be grouped into "intrinsic" basal and luminal molecular subtypes. Here, we provide an overview of the subtypes and discuss their biological and clinical properties.

RECENT FINDINGS

Basal cancers are characterized by advanced stage and metastatic disease at presentation. They tend to be enriched with squamous and small cell/neuroendocrine features and inactivating mutations and deletions of TP53 and RB1. Basal cancers can be divided into "epithelial" and "mesenchymal" (also known as "claudin low") subsets, and a portion of the latter form a "neuroendocrine/neuronal" subset that is associated with particularly poor survival. Luminal cancers are often enriched with papillary histopathological features and activating mutations in FGFR3, and they can also be divided into additional subsets based on differential stromal cell infiltration, relative genomic instability, and high- versus low-level expression of carcinoma in situ (CIS) gene expression signatures. Importantly, the bladder cancer molecular subtypes display differential sensitivities to neoadjuvant chemotherapy and immune checkpoint blockade, and preliminary data also suggest that they respond differently to radiation with or without hypoxia modulation. Ongoing studies are investigating the relevance of the molecular subtypes to the bladder cancer histopathological variants and to upper tract urothelial cancer. The bladder cancer molecular subtypes were associated with different prognoses and responses to conventional and targeted therapies in retrospective studies. If validated in prospective studies, molecular subtyping will be integrated into bladder cancer clinical management.

[Small cell neuroendocrine carcinoma of the bladder: Report of five cases and a review of the literature]

Neuroendocrine small cell carcinoma of the bladder is a rare and aggressive tumour, accounting for less than 1% of all bladder tumours. Given its rarity and the absence of randomized trials, the therapeutic management of these tumours remains difficult. By analogy with small cell lung cancer, multimodal treatment is often proposed. Radical cystectomy plus chemotherapy and chemoradiation therapy are associated with better survival compared to monotherapy. We report our experience in the management of these tumours with literature review.

Differential expression of neuroendocrine markers, TTF-1, p53, and Ki-67 in cervical and pulmonary small cell carcinoma

Small cell carcinoma (SCC) is a highly malignant neuroendocrine tumor that may occur in many anatomic sites of the body.In this study, we compared the different expression of neuroendocrine markers, thyroid transcription factor 1 (TTF-1), p53, and Ki-67 in 23 cases of cervical SCC and 56 cases of pulmonary SCC using immunohistochemistry.Our study showed that cervical SCC had a younger onset age than pulmonary counterpart. Although both had the similar morphological features, different immunohistochemical expression panel was observed in this study. As neuroendocrine tumors, SCC of cervix and lung had similar immunoreactive staining for CD56 and chromogranin A, but the expression of the synaptophysin in cervical SCC was significantly higher than that in pulmonary SCC (P = .007). The TTF-1 expression of pulmonary SCC illustrating diffuse and strong positivity in tumor cell nuclei was significantly higher than that of the cervical SCC (P = .003). There was only 1 case showing p53 protein over-expression in the 23 cases of cervical SCC, and p53 over-expression was observed in 42.9% of pulmonary SCC (P = .001). Only 9 cases of cervical SCC showed ≥80% of the Ki-67 proliferation index, while it was found in 94.6% of pulmonary SCC (P < .001).The different immunohistochemical expressions of these 2 kinds of SCCs may be related with their pathogenetic mechanism, and these differences may be helpful in the identification of the origins of the metastatic SCC with unknown primary site.

Nomograms to Predict Individual Prognosis of Patients with Primary Small Cell Carcinoma of the Bladder

Objectives: To develop reliable nomograms to estimate individualized overall survival (OS) and cancer specific survival (CSS) for patients with primary small cell carcinoma of the bladder (SCCB) and compare the predictive value with the AJCC stages.

Patients and Methods: 582 eligible SCCB patients identified in the Surveillance, Epidemiology, and End Results (SEER) dataset were randomly divided into training (n=482) and validation (n=100) cohorts. Akaike information criterion was used to select the clinically important variables in multivariate Cox models when establishing nomograms. The performance of nomograms was bootstrapped validated internally and externally using the concordance index (C-index) with 95% confidence interval (95% CI) and calibration curves and was compared with that of the AJCC stages using C-index, Kaplan-Meier curves and decision curve analysis (DCA).

Results: Two nomograms shared common indicators including age, tumor size, T stage, lymph node ratio, metastases, chemotherapy, radiation and radical cystectomy, while marriage and gender were only incorporated in the OS nomogram. The C-indices of nomograms for OS and CSS were 0.736 (95%CI 0.711-0.761) and 0.731(95%CI 0.704-0.758), respectively, indicating considerable predictive accuracy. Calibration curves showed consistency between the nomograms and the actual observation. The results remained reproducible when nomograms were applied to the validation cohort. Additionally, comparisons between C-indices, Kaplan-Meier curves and DCA proved that the nomograms obtained obvious superiority over the AJCC stages with wide practical threshold probabilities.

Conclusions: We proposed the first two nomograms for individualized prediction of OS and CSS in SCCB patients with satisfactory predictive accuracy, good robustness and wide applicability.

The prognostic value of histological subtype in patients with metastatic bladder cancer

We aim to evaluate the prognostic effect of the histological sub-type in patients with metastatic bladder cancer based on the Surveillance Epidemiology and End Results database. A total of 2634 eligible patients were included. The histological subtypes were: transitional cell carcinoma (TCC; 75.2%); adenocarcinoma (3.3%); squamous cell carcinoma (SQCC; 4.1%); and small cell carcinoma (4.3%). A significant association of adenocarcinoma with better survival outcomes (P < 0.015), and that of SQCC with worse outcomes (P < 0.001) was observed. On multivariate analysis, adenocarcinoma was significantly associated with longer and SQCC with shorter survival time as compared to TCC. Overall, 1331 (50.5%) patients had a single metastatic site and 523 (19.9%) had multiple sites involved. Single-site metastasis had a better survival outcome than multiple metastases (P < 0.001). Histological sub-type and presence of multiple metastatic sites are independent predictors of survival time. Prospective, in-depth research is needed to determine optimal therapeutic strategies for different histological subtypes of bladder cancer with different metastatic patterns.

A validation and extended description of the Lund taxonomy for urothelial carcinoma using the TCGA cohort

Global gene expression analysis has been a major tool for urothelial carcinoma subtype discovery. This approach has revealed extensive complexity both in intrinsic features of the tumor cells and in the microenvironment. However, global gene expression cannot distinguish between gene expression signals originating from the tumor cells proper and from normal cells in the biopsy. Here, we use a large cohort of advanced urothelial carcinomas for which both gene expression data and extensive immunohistochemistry are available to create a supervised mRNA expression centroid classifier. This classifier identifies the major Lund taxonomy tumor cell phenotypes as defined by IHC. We apply this classifier to the independent TCGA dataset and show excellent associations between identified subtypes and genomic features. We validate a progressed version of Urothelial-like A (UroA-Prog) that shows FGFR3 mutations and CDKN2A deletions, and we show that the variant Urothelial-like C is almost devoid of FGFR3 mutations. We show that Genomically Unstable tumors are very distinct from Urothelial-like tumors at the genomic level, and that tumors classified as Basal/SCC-like all complied with the established definition for Basal/SCC-like tumors. We identify the Mesenchymal-like and Small-cell/Neuroendocrine-like subtypes, and demonstrate that patients with UroB and Sc/NE-like tumors show the worst overall survival.

Long term disease free survival with multimodal therapy in small cell bladder cancer

Background

Small cell bladder cancer (SCBC) is an aggressive subtype accounting for less than 1 % of all bladder malignancies associated with rapid progression, early metastases formation and high mortality rates.

Case presentation

We present an unusual long term disease free survival of a 60 year-old man who was diagnosed with SCBC two and a half years ago. He underwent four cycles of cisplatin/etoposide chemotherapy as well as a prophylactic whole-brain radiotherapy followed by a radical cystoprostatectomy and ileal neobladder with extended pelvic lymphadenectomy. Since 33 months the patient is now recurrence-free.

Conclusion

In this case report, we were able to show that early multimodal therapy results in long term disease free survival, thus we highly recommend neoadjuvant chemotherapy as a part of multimodal management of a primary metastases-free, localized and surgically resectable SCBC.

Variant histology in bladder cancer: how it should change the management in non-muscle invasive and muscle invasive disease?

Bladder cancer (BC) is a frequent type of carcinoma with an estimated incidence of approximately 100,000 men and women each year in the European Union (EU) with an associated mortality of 30,000 of these patients. In more than 70% the disease is diagnosed in a non-muscle invasive stage with the chance of minimally invasive, local treatment only, which might be required repetitively due to high rate of recurrence. In contrast, muscle invasive or metastatic stages need multimodal treatment strategies including surgical treatment and chemotherapy (CTX) in neoadjuvant (NAC), adjuvant, or palliative settings. Therapy recommendations and guidelines mainly refer to the most common histological type of BC, pure urothelial carcinoma (UC). However, BC can be classified as urothelial and non-UC. Non-urothelial BC and variants of UC account for up to 25% of all BCs. Further discrimination can be made into epithelial and non-epithelial non-UC. Most of the non-UCs are of epithelial origin (approximately 90%) including squamous-cell carcinoma, adenocarcinoma and small-cell carcinoma. Non-epithelial tumors are rare and include variants as sarcoma, carcinosarcoma, paraganglioma, melanoma and lymphoma. Even though it is unclear whether the prognosis of non-urothelial cancer truly differs from that of UC, there is evidence that additional variant histology might prognosticate an impaired prognosis. Accordingly, aggressive behavior and often advanced stages at primary presentation are frequently observed in non-UC arguing for radical and sometimes different treatment strategies as compared to pure UC. This review aims to summarize the available data for the most common histological variants of non-urothelial BC.

Small-Cell Carcinoma of the Bladder: 20-Year Single-Institution Retrospective Review

INTRODUCTION

Small-cell carcinoma of the bladder is a poorly differentiated neoplasm with aggressive behavior. We analyzed clinical outcomes of patients who were treated at our institution to identify an optimal treatment strategy.

MATERIALS AND METHODS

Retrospective chart analysis was performed for patients who were treated for small-cell carcinoma of the bladder at Fox Chase Cancer Center between 1995 and 2015. Survival was compared between different treatment periods (before January 2010 vs. after January 2010) and different treatment modalities (surgery vs. neoadjuvant chemotherapy vs. radiation).

RESULTS

Thirty-eight patients were treated for small-cell carcinoma of the bladder at our institution during the 20-year study period. Median survival was 11.8 months and overall survival rates after 1, 3, and 5 years were 46.6%, 26.2%, and 14%, respectively. Survival analysis adjusted for age, histology, and stage showed that no single treatment strategy was significantly superior (95% confidence interval [CI], 0.26-3.03; P = .860 for surgery; 95% CI, 0.31-2.87; P = .928 for neoadjuvant chemotherapy; 95% CI, 0.65-5.49; P = .238 for radiation). In separate analyses of long-term survivors, we found that most received platinum-based neoadjuvant chemotherapy followed by radical cystectomy. Among the 20 patients who received neoadjuvant chemotherapy, downstaging occurred in 9 (45%).

CONCLUSION

Although none of the treatment options were found to be significantly superior with respect to survival, neoadjuvant chemotherapy might halt the progression of the disease until cystectomy and lead to downstaging. At our institution, the best outcomes were observed in patients who received neoadjuvant platinum-based chemotherapy combined with radical cystectomy.

Advanced small cell carcinoma of the bladder: clinical characteristics, treatment patterns and outcomes in 960 patients and comparison with urothelial carcinoma

To describe the clinical characteristics, treatment patterns and outcomes in advanced small cell bladder cancer (aSCBC) patients and compare to those with urothelial carcinoma (UC). Individuals in the National Cancer Data Base with a diagnosis of either nodal (TxN+M0) or distant metastatic (TxNxM1) disease were identified from 1998 to 2010. We assessed the relationships between stage, treatment modalities and survival in the aSCBC cohort and compared these to UC patients. In the 960 patient aSCBC cohort (62% M1), 50% received palliative therapy alone, 68% in M1 versus 21% in M0 groups (P < 0.0001). Single modality local therapy (15%) and surgical (21%) or radiation-based (14%) multimodal therapy (MMT) were used in the other 50%. Cystectomy-based MMT was utilized in 45% of N+M0 versus 6.4% of NxM1 patients (P < 0.0001). Median overall survival (OS) for aSCBC patients was 8.6 months; 13.0 months in N+M0 versus 5.3 months in NxM1 patients (P < 0.0001). Survival was similar between TxN1M0 and TxN2-3M0 patients (14.8 months vs. 12.1 months, P = 0.15). Urothelial carcinoma patients (n = 27,796, 45% M1) lived longer compared to aSCBC patients in the N+M0 group (17.3 months vs. 13.0 months, P = 0.0007). There were not clinically significant differences in OS between UC and aSCBC patients in the M1 group. Advanced SCBC is a rare disease with a poor survival and palliative therapy is common, especially in M1 patients. In comparison to UC, the outcomes for aSCBC patients are worse in those with lymph node only involvement but similar in those with distant disease.