Chromosomal imbalances in small cell carcinomas of the urinary bladder

Primary Small Cell Carcinoma of the Kidney: Disease Characteristics and Treatment Outcomes

Background: Primary small cell carcinoma of the kidney (PSCCK) is exceedingly rare and data on disease characteristics and outcomes are sparse. This study examines a nationally-representative cancer registry to better characterize PSCCK. Methods: We queried the National Cancer Database to identify patients with histology-confirmed PSCCK from 2004 to 2015. Adjusted Cox proportional hazards regression and Kaplan–Meier analyses were employed to assess predictors of mortality and estimate median survival time, respectively. Results: A total of 110 patients were included (47:53% female:male, 77% ≥60 years of age, 86% Caucasian). Significant predictors of mortality included female sex, age 60–69 years, treatment at an Integrated Network Cancer Program, stage cM1, and lack of surgical and chemoradiotherapy treatment. Independent protective factors were high socioeconomic status and treatment at an Academic Research Program. The estimated median overall survival time was 9.31 (95% CI 7.28–10.98) months for all patients. No differences in estimated survival time were observed across individual treatment modalities among those patients who underwent treatment (p = 0.214). Conclusions: PSCCK is an aggressive malignancy with a median survival time of less than one year. Future studies that correlate clinical tumor staging with specific treatment modalities are needed to optimize and individualize management.

Immune Exclusion Is Frequent in Small-Cell Carcinoma of the Bladder

Small-cell cancer of the urinary bladder is a rare but highly aggressive disease. It is currently unclear whether immune checkpoint therapies that have been approved for urothelial carcinomas will also be efficient in small-cell carcinomas. In this study, we analyzed potential predictors of response including PD-L1 expression and the quantity and location of tumor-infiltrating lymphocytes (TILs) in 12 small-cell and 69 “classical” urothelial cancers by immunohistochemistry. The analysis revealed that small-cell carcinomas were characterized by the virtual absence of PD-L1 expression and an “immune-excluded” phenotype with only a few TILs in the center of the tumor (CT). In small-cell carcinomas, the average immune cell density in the CT (CD3: 159 ± 206, CD8: 87 ± 169 cells/mm²) was more than 3 times lower than that in the urothelial carcinomas (CD3: 625 ± 800, p < 0.001; CD8: 362 ± 626 cells/mm², p = 0.004) while there was no significant difference in the immune cell density at the invasive margin (IM) (small-cell carcinomas CD3: 899 ± 733, CD8: 404 ± 433 cells/mm²; urothelial carcinomas CD3: 1167 ± 1206, p = 0.31; CD8: 582 ± 864 cells/mm², p = 0.27). Positive PD-L1 staining was found in 39% of urothelial cancers, but in only 8% of small-cell bladder cancer cases (p = 0.04). Concordant with these data, a sharp decrease of PD-L1 positivity from >80% to 0% positive cells and of TILS in the CT from 466-1063 CD3-positive cells/mm² to 50-109 CD3-positive cells/mm² was observed in two cancers with clear-cut progression from “classical” urothelial to small-cell carcinoma. In conclusion, these data demonstrate that small-cell bladder cancer commonly exhibits an immune-excluded phenotype.

Whole-Exome Sequencing of Sinonasal Small Cell Carcinoma Arising within a Papillary Schneiderian Carcinoma In Situ

OBJECTIVE

The pathogenetic underpinnings of extrapulmonary small cell carcinomas (EPSCCs) of the head and neck are poorly understood. We sought to describe the clinical case and whole-exome DNA sequencing data of a patient with sinonasal Schneiderian carcinoma in situ whose tumor progressed to small cell carcinoma (SCC).

STUDY DESIGN

Case report and whole-exome sequencing of tumor DNA.

SETTING

Academic medical center.

SUBJECTS AND METHODS

A 52-year-old man with sinonasal Schneiderian carcinoma in situ whose tumor progressed to small cell carcinoma. We performed whole-exome genetic sequencing and copy-number variation (CNV) analysis of tumor and normal DNA extracted from flash-frozen, paraffin-embedded (FFPE) samples.

RESULTS

A total of 93 high-confidence, nonsynonymous somatic mutation events were identified in sinonasal SCC, including loss-of-function mutations in TP53, MAML3, a transcriptional coactivator of the Notch pathway, and GAS6, an activating ligand of the TAM family of tyrosine kinase receptors. Focal amplifications of chromosomal regions 6p25-11.1, containing SOX4 and VEGFA, and 14q32.1-32.3, containing AKT1 and the Notch inhibitory ligand DLK1, were also seen. Further CNV analysis revealed deletions in the critical cell cycle regulators CDKN2A, RB1, RBL1, and RBL2 and the chromatin modifier EP300.

CONCLUSIONS

Small cell carcinoma may rarely arise from sinonasal Schneiderian carcinoma in situ and exhibits similar genomic aberrations (eg, SOX amplification, Notch pathway inactivation) to pulmonary small cell carcinoma.

Neuroendocrine Carcinoma of the Kidney and Bladder with Loss of Heterozygosity and Changes in Chromosome 3 Copy Number

Patient: Female, 77

Final Diagnosis: Neuroendocrine carcinoma of the kidney and bladder

Symptoms: Right lumbar pain

Medication: None

Clinical Procedure: CT • needele biopsy of renal tumor • transyrethral resection of bladder tumor

Specialty: Urology

Small cell carcinoma of the urinary bladder: a contemporary review with a special focus on bladder-sparing treatments

Small cell carcinoma of the urinary bladder (SCCUB) is a rare and aggressive disease. To date, no standard treatment has been proposed due to the lack of prospective studies resulting from the rarity of this disease. Recently published studies of relatively large patient cohorts, however, have shed some light on the management of SCCUB patients. In this article, the authors review the epidemiology, pathogenesis, diagnosis and treatment (based on disease stage), and they then discuss the optimal therapeutic strategy for SCCUB patients, particularly for those with limited, locoregional disease. The authors conclude that multidisciplinary approaches are needed for the optimal management of this aggressive disease. The authors also discuss bladder-sparing approaches for SCCUB patients, compared to those for conventional bladder urothelial carcinoma patients.

Clinical outcome of primary small cell carcinoma of the urinary bladder

Purpose

Primary small cell carcinoma of the urinary bladder is a rare malignant disease. It accounts for less than 1% of all urinary bladder carcinomas. The purpose of this study is to review the clinical features, the treatment modalities, and the overall survival of these patients. We also compare the clinical outcomes between patients of bladder small cell carcinoma (SCC) and bladder urothelial carcinoma (UC).

Materials and methods

We reviewed the charts of patients with bladder tumors from January 1995 to December 2012 in the Chang Gung Memorial Hospital. A total of 2421 malignant bladder tumor patients were reviewed and there were 18 patients who were diagnosed with primary bladder SCC. The patients’ characteristics, including age, gender, smoking history, presented symptoms, tumor size, locations, clinical stages, treatment modalities, pathology appearance, recurrence conditions, and survival conditions were all recorded. We also compared the clinical outcomes and the overall survival rates between patients with bladder SCC and those with UC.

Results

Bladder SCC accounted for about 0.74% of all bladder malignancies in our institution. The mean age at diagnosis was 70.67 years, and the male-to-female ratio was 2.6:1. Thirteen patients had a history of cigarette smoking. All patients presented with symptoms of gross hematuria, and three of them had bladder tamponade requiring blood clot evacuation by cystoscopy. Only one patient had T1 disease, ten patients had stage III disease, and seven patients had lymph node or distant metastasis (stage IV disease). The mean tumor size was 4.29 cm in diameter. For the majority (61.11%) of patients, SCC coexisted with UC components. The average survival time was 10.92 months. Patients with bladder SCC had worse overall survival rates than those of stage III and stage IV bladder UC. Performing radical cystectomy does not significantly improve their overall survival rates. None of the clinicopathologic parameters, including the presence of coexisting nonsmall cell carcinoma component (P = 0.831), receiving radical cystectomy (P = 0.194), distant metastasis (P = 0.062), and gender (P = 0.564), were significantly associated with survival.

Conclusion

SCC of the urinary bladder is a rare condition, and standard treatment outlines have not been well established. Most of the presented cases have a very poor prognosis. Prospective, multi-institutional, randomized studies are required to assess better treatment modalities. To the best of our knowledge, this is the largest reported case analysis of primary bladder SCC in a Taiwanese population.

Identification of prefoldin amplification (1q23.3-q24.1) in bladder cancer using comparative genomic hybridization (CGH) arrays of urinary DNA

BACKGROUND

Array-CGH represents a comprehensive tool to discover genomic disease alterations that could potentially be applied to body fluids. In this report, we aimed at applying array-CGH to urinary samples to characterize bladder cancer.

METHODS

Urinary DNA from bladder cancer patients and controls were hybridized on 44K oligonucleotide arrays. Validation analyses of identified regions and candidates included fluorescent in situ hybridization (FISH) and immunohistochemistry in an independent set of bladder tumors spotted on custom-made tissue arrays (n = 181).

RESULTS

Quality control of array-CGH provided high reproducibility in dilution experiments and when comparing reference pools. The most frequent genomic alterations (minimal recurrent regions) among bladder cancer urinary specimens included gains at 1q and 5p, and losses at 10p and 11p. Supervised hierarchical clustering identified the gain at 1q23.3-q24.1 significantly correlated to stage (p = 0.011), and grade (p = 0.002). The amplification and overexpression of Prefoldin (PFND2), a selected candidate mapping to 1q23.3-q24.1, correlated to increasing stage and tumor grade by means of custom-designed and optimized FISH (p = 0.013 and p = 0.023, respectively), and immunohistochemistry (p ≤0.0005 and p = 0.011, respectively), in an independent set of bladder tumors included in tissue arrays. Moreover, PFND2 overexpression was significantly associated with poor disease-specific survival (p ≤0.0005). PFND2 was amplified and overexpressed in bladder tumors belonging to patients providing urinary specimens where 1q23.3q24.1 amplification was detected by array-CGH.

CONCLUSIONS

Genomic profiles of urinary DNA mirrowed bladder tumors. Molecular profiling of urinary DNA using array-CGH contributed to further characterize genomic alterations involved in bladder cancer progression. PFND2 was identified as a tumor stratification and clinical outcome prognostic biomarker for bladder cancer patients.

Small cell bladder cancer: biology and management

Small cell bladder cancer (SCBC) is a rare and aggressive form of bladder cancer. It exhibits similar biological behavior to small cell lung carcinoma. Untreated, it is associated with a very poor prognosis. Appropriate oncologic surgery remains the mainstay of treatment of this disease but is not curative alone in the majority of the cases. Adding systemic therapy to the treatment regimen has been shown to improve survival. The most common chemotherapy regimens used in published series include a platinum complex plus etoposide, although doxorubicin-based regimens and standard urothelial cancer regimens also have been associated with response. Despite robust chemotherapy responses, metastatic disease is associated with relapse and a median overall survival of 18 months or less. Better understanding of the molecular alterations driving SCBC may facilitate the development of new therapeutic strategies and improved outcomes.

Small cell carcinoma of the kidney: a clinicopathologic study of 14 cases

Small cell carcinoma of the kidney is distinctively rare. We searched pathology files in 2 institutions and found 14 cases of renal small cell carcinoma. The patients' mean age at diagnosis was 59 years (range, 22-75 years); 8 were women, and 6 were men. Patients usually presented with hematuria (n = 6) and abdominal pain (n = 5). The mean tumor size was 7.1 cm (range, 3.5-14.0 cm). The small cell carcinoma was pure in 9 cases and mixed with high-grade urothelial carcinoma in 5 cases. None was associated with any type of renal cell carcinoma. Tumor necrosis was present in all cases, and lymphovascular invasion was identified in 6 cases. The tumor invaded the perinephric adipose tissue in 13 cases and was confined to the kidney in only 1 case. Lymph node metastases were identified in all patients who underwent lymph node dissection (5/5). On immunostains, the small cell carcinoma cells were positive for pancytokeratin (11/12), chromogranin (6/9), and synaptophysin (8/9). Follow-up data were available for 13 patients, and 11 died of small cell carcinoma at a mean of 15 months (range, 4-31 months) after diagnosis. Of the 2 surviving patients, 1 was alive at 5 months after diagnosis, and the other, whose disease was confined to the kidney, was alive with no evidence of disease at 137 months. In summary, renal small cell carcinoma is a highly aggressive disease that often presents at an advanced stage with widespread metastases. Patients usually have a poor clinical outcome despite multimodal therapy. The frequent coexistence of small cell carcinoma with urothelial carcinoma suggests that renal small cell carcinomas may evolve from a preexisting urothelial carcinoma.

A rare bladder cancer--small cell carcinoma: review and update

Small cell carcinoma of the bladder (SCCB) is rare, highly aggressive and diagnosed mainly at advanced stages. Hematuria is the main symptom of this malignancy. The origin of the disease is unknown; however the multipotent stem cell theory applies best to this case. Histology and immunohistochemistry shows a tumour which is indistinguishable from small cell lung carcinoma (SCLC). Coexistence of SCCB with other types of carcinoma is common. The staging system used is the TNM-staging of bladder transitional cell carcinoma. The treatment is extrapolated from that of SCLC. However, many patients with SCCB undergo radical resection which is rarely performed in SCLC. Patients with surgically resectable disease (< or = cT1-4aN0M0) should be managed with multimodal therapy associating chemotherapy, surgery and/or radiotherapy. Neoadjuvant chemotherapy using four chemotherapy cycles followed by radical cystectomy is the most effective therapeutic sequence. Patients with unresectable disease (> or = cT4bN+M+) should be managed with palliative chemotherapy based on neuroendocrine type regimens comprising a platinum drug (cisplatin in fit patients). The prognosis of the disease is poor mainly in the case of pure small cell carcinoma. Other research programs are needed to improve the outcome of SCCB.

Pure Small Cell Carcinoma of the Bladder: A Case Report

Small cell carcinoma of the urinary bladder is an uncommon tumor that has been described in case reports or small series. We report a new case in a 67-year-old male who presented with gross hematuria and irritative symptoms. Cystoscopy revealed an extensive mass of the bladder and computed tomography scan showed an important thickening of the bladder wall. Diagnosis of small cell carcinoma was established after radical cystectomy and microscopic examination. The patient received pelvic hemostatic radiotherapy and platinium-based chemotherapy. Three months after the diagnosis, he developed bone, renal and adrenal metastases.

Outcome of recurrent and metastatic small cell carcinoma of the bladder

BACKGROUND

Bladder small cell carcinoma is an uncommon tumour. Through a retrospective study we will present the evolution of recurrent and metastatic disease and outcome of patients treated at Léon-Bérard Cancer Centre.

METHODS

Only 15 patients having recurrent or metastatic bladder small cell carcinoma were treated at Léon-Bérard Cancer Centre between 1996 and 2007. The patients were divided in two groups: a mixed small cell carcinoma group (9 patients) and a pure small cell carcinoma group (6 patients). All the records and informations related to treatment and outcome of the 15 patients were retrospectively analyzed. Various characteristics of small cell carcinoma were investigated.

RESULTS

The median age of the 15 patients having recurrent or metastatic bladder small cell carcinoma and treated at Léon-Bérard Cancer Centre was 63 years and the disease was at stage IV for all cases. Nine patients were treated by chemotherapy. Four patients were treated by local radiotherapy (3 with radiotherapy without previous surgery and 1 with surgery followed by radiotherapy) and chemotherapy. One patient was treated by whole brain radiotherapy. And one patient died before treatment. After 52.4 months median follow up, 12 patients died. Median overall survival was 7.6 months. Survival probability at 1 year was 33%. Median overall survival was 9.9 months in the mixed small cell carcinoma group, and was only 4.6 months in the pure small cell carcinoma group. Survival probability at 1 year in the mixed small cell carcinoma group was 44% as compared to 17% in the pure small cell carcinoma group (Log-rank test: p = 0.228).

CONCLUSION

Recurrent and metastatic bladder small cell carcinoma is associated with very poor prognosis. The pure bladder small cell carcinoma appears to have poorer outcome than the mixed bladder small cell carcinoma. Chemotherapy using platinum drugs is a mainstay treatment.

Histological variants of urothelial carcinoma: diagnostic, therapeutic and prognostic implications

It is well established that invasive urothelial carcinoma, involving the urinary bladder and renal pelvis, has marked propensity for divergent differentiation. In recent years, several 'variant' morphologies have been described and most have been recognized in the 2004 World Health Organization Classification. These histological variants of urothelial carcinoma have clinical significance at various levels, including diagnostic, that is, awareness of the morphological variant is essential in order to avoid diagnostic misinterpretations; prognostic for patient risk stratification; and therapeutic, where a diagnostic assignment of a particular variant may be associated with the administration of a therapy distinctive from that used in conventional invasive urothelial carcinoma. The diagnoses of micropapillary urothelial carcinoma, small-cell carcinoma, lymphoepithelioma-like carcinoma and sarcomatoid carcinoma are prime examples where treatment protocols may be different than the usual muscle-invasive bladder cancer. This review discusses the variants of urothelial carcinoma, outlining for each the diagnostic features, differential diagnostic considerations and the clinical significance.

Overexpression of EIF-5A2 predicts tumor recurrence and progression in pTa/pT1 urothelial carcinoma of the bladder

The authors investigated the status of abnormalities of eIF-5A2 gene in superficial (pTa/pT1) urothelial carcinoma of the bladder (UC), as well as its correlation with clinicopathologic variables and patient outcome. The methods of immunohistochemistry (IHC), fluorescence in situ hybridization (FISH), reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were utilized to examine protein/mRNA(messenger RNA) expression and amplification of eIF-5A2 in a cohort of pTa/pT1 UCs. Overexpression of EIF-5A2 was examined by IHC in 38/112 (33.9%) pTa/pT1 UCs. A significant association of overexpression of EIF-5A2 with shortened UC patient recurrence-free survival (P = 0.002), as well as with shortened progression-free survival (P = 0.004), was demonstrated. Importantly, multivariate Cox regression analysis revealed that EIF-5A2 expression provided a significant independent prognostic parameter either in tumor recurrence (P = 0.002) or in tumor progression (P = 0.007). FISH results demonstrated that eIF-5A2 amplification was detected in 5/59 of the informative UCs; in each of the five cases with eIF-5A2 amplification, overexpression of EIF-5A2 was observed. In the remaining 54 UCs without eIF-5A2 amplification, 16 cases were also observed to have overexpression of EIF-5A2. In 13 pairs of UC and adjacent normal tissues, eight UCs were examined and showed up-regulated eIF-5A2 mRNA by RT-PCR, while increased expression of EIF-5A2 protein was only detected in 4/8 UCs by Western blotting. These findings suggest that overexpression of EIF-5A2, as detected by IHC, may predict tumor recurrence and progression in pTa/pT1 UC patients, and the protein expression of eIF-5A2 might be regulated not only by gene amplification, but also by other molecular mechanisms.

Overexpression of EIF-5A2 is an independent predictor of outcome in patients of urothelial carcinoma of the bladder treated with radical cystectomy

BACKGROUND

Our previous study has suggested an oncogenic role of eIF-5A2 in ovarian tumorigenesis. Abnormalities of eIF-5A2 and its clinical/prognostic significance, however, in urothelial carcinoma of the bladder (UC) are unclear.

METHODS

In this study, the methods of reverse transcription-PCR, immunohistochemistry, and fluorescence in situ hybridization were used to examine mRNA/protein expression and amplification of eIF-5A2 in a large cohort of UCs treated with radical cystectomy.

RESULTS

Up-regulated expression of eIF-5A2 mRNA was observed in 50% (8 of 16) of UCs, when compared with adjacent normal bladder tissues. Overexpression of EIF-5A2 protein and amplification of eIF-5A2 was examined informatively in 45.3% (39 of 86) and 10.6% (5 of 47) of UCs, respectively. In univariate survival analysis of the UC cohorts, a significant association of overexpression of EIF-5A2 with shortened patient survival (mean, 38.2 months versus 52.9 months, P = 0.001, log-rank test) was shown. In different subsets of UC patients, overexpression of EIF-5A2 was also a prognostic indicator in grade 1/2 (P = 0.0009) and grade 3 (P = 0.016) tumor patients, and in pT1 (P = 0.0089), pT2 (P = 0.0354), pT3/4 (P = 0.0058), pN0 (P = 0.0039), and pN1-2 (P = 0.0093) tumor patients. Importantly, EIF-5A2 expression (P = 0.0007) together with pT stage (P = 0.0001) provided significant independent prognostic variables in multivariate analysis.

CONCLUSIONS

These findings indicate that overexpression of EIF-5A2 in UCs is coincident with acquisition of a poor prognostic phenotype, suggesting that the expression of EIF-5A2, as detected by immunohistochemistry, is an independent molecular marker for shortened survival time of UC patients treated with radical cystectomy.

A case of uterine cervical adenocarcinoma associated with small cell carcinoma

Extrapulmonary small cell carcinomas are often associated with carcinomas of other cell types. Although a hypothesis that extrapulmonary small cell carcinomas arise from a multipotential stem cell could explain this mixed feature, recent molecular evidence supports another possibility that the small cell component may arise as a late-stage phenomenon in the progression of more organ-typical carcinomas. Here, we report a case of uterine cervical adenocarcinoma containing 30% of small cell carcinoma. Adenocarcinoma was located in the endometrial side of the tumor that was adjacent to the normal cervical region, while small cell carcinoma was located in the periphery of the tumor. The transition from adenocarcinoma to small cell carcinoma was observed in the boundary area. These findings suggest that cervical small cell carcinoma can be differentiated from pre-existing adenocarcinoma and offer further support to the hypothesis that the small cell component arises as a late-stage phenomenon in the progression of more organ-typical carcinomas.

The many faces of urothelial carcinoma: an update with an emphasis on recently described variants

Urothelial carcinoma is well known for its divergent differentiation. Several "variant" morphologies have been described in the literature in recent years and have additionally been recognized in the recent World Health Organization classification of urothelial neoplasms. The importance of recognizing these variant histologies lies in the potential diagnostic, prognostic, or therapeutic implications that accompany these diagnoses. The range of variant morphology seen in the urinary bladder may also be seen in urothelial tumors of the renal pelvis. Herein we review select variants of urothelial carcinoma focusing on the relatively recently recognized variants, outlining the diagnostic features, common differential diagnostic dilemmas, and clinical relevance. This review also includes a discussion on variants on which there is recent information available.

Small cell carcinoma of the urinary bladder--histogenesis, genetics, diagnosis, biomarkers, treatment, and prognosis

Small cell carcinoma of the urinary bladder is a rare but highly aggressive malignancy with a dismal prognosis. Most patients present with advanced disease at the time of diagnosis. Hematuria is the most frequent presenting symptom. Histologically, small cell carcinoma of the urinary bladder is indistinguishable from its pulmonary counterpart. Coexistence with other types of carcinoma is common. Histogenesis is uncertain; there are several competing theories, including origin from stem cells, from urothelial cells, and from neuroendocrine cells in normal or metaplastic urothelium. The molecular pathogenesis remains unclear. Immunohistochemical staining can be extremely helpful in establishing the diagnosis, and in investigating the use of potential therapeutic strategies. Currently, combinations of surgical resection, chemotherapy, and radiation therapy represent the main treatment options. The recent observation of c-kit and epidermal growth factor receptor expression in more than 25% of patients with urinary bladder small cell carcinoma opens new avenues for further investigation. Improvement in survival may depend upon the identification of new molecular markers to facilitate earlier diagnosis and the development of novel targeted therapies. In this paper, we review general aspects of small cell carcinoma of the urinary bladder, focusing on the ways in which our understanding of this entity has been positively influenced by studies of the histopathologic and immunohistochemical findings, and by investigations of genetic alterations in this disease.

The pathology of extrapulmonary small cell carcinoma

Extrapulmonary small cell carcinomas (EPSCCs) are uncommon malignant neoplasms with a reported incidence of 0.1% to 0.4% in the United States. Since their first description in 1930, they have been seen in nearly every organ system. Like their more common pulmonary counterparts, EPSCCs are thought to arise from a multipotential stem cell. However, there is recent molecular evidence that small cell elements may arise as a late-stage phenomenon in the genetic progression of more organ-typical carcinomas. The morphologic, immunohistochemical, and ultrastructural features are similar to those described in pulmonary small cell carcinomas (PSCCs). The differential diagnosis of EPSCC includes PSCC, other neuroendocrine tumors, small round blue cell tumors, metastatic melanoma, lymphoma, and poorly differentiated non-small cell carcinomas. Molecular alterations reported to occur in EPSCCs include abnormalities described in PSCC and changes found in carcinomas more typically encountered in the organ from which they arise. In this article we discuss the pathology of EPSCC with a review of theories of histogenesis, sites of occurrence, diagnostic features, differential diagnosis, molecular alterations, and clinical behavior.

Small-cell carcinoma of the urinary bladder: diagnosis and management

Small-cell carcinoma of the urinary bladder (SCCUB) accounts for less than 1% of all cancers arising in the urinary bladder. Current diagnosis and management of SCCUB are often patterned after small-cell lung cancer (SCLC). However, SCCUB therapy is different from that for SCLC. For example, many patients with SCCUB undergo local resection, which is rarely performed in SCLC. As in SCLC, platinum-etoposide combination chemotherapy is employed as the main systemic treatment option for SCCUB. Chemotherapy is usually combined with other therapeutic modalities, especially in patients whose disease is limited to the locoregional area. Owing to the rarity of this malignancy, no prospective study has been performed that establishes the efficacy and duration of chemotherapy or the relative efficacy of platinum-etoposide versus other chemotherapeutic regimens. This article provides a comprehensive review of the current status of SCCUB diagnosis and management, as well as some unique insights into this rare tumor.

Epidermal Growth Factor Receptor Protein Expression and Gene Amplification in Small Cell Carcinoma of the Urinary Bladder

PURPOSE

Small cell carcinoma of the urinary bladder is a highly aggressive malignancy with an average life expectancy of only a few months. Epidermal growth factor receptor (EGFR) has been implicated in the pathogenesis and progression of many malignancies. This study was done to investigate EGFR protein expression and gene amplification in a large series of small cell carcinomas of the urinary bladder.

EXPERIMENTAL DESIGN

Fifty-two cases of urinary bladder small cell carcinoma were included in this study. Immunostaining for EGFR was done on paraffin-embedded tissue sections, and gene amplification for EGFR was done by fluorescence in situ hybridization. EGFR expression was correlated with clinicopathologic characteristics and clinical outcome.

RESULTS

All 52 patients, except 1, had advanced disease (T2 or above) at presentation. Immunohistochemically, positive EGFR expression was observed in 14 of 52 (27%) cases. No EGFR gene amplification was observed in any of 52 cases by fluorescence in situ hybridization. Forty cases had polysomy and the remaining 12 cases displayed disomy. No correlation between EGFR protein expression and gene amplification was shown. There was no correlation between EGFR expression and clinicopathologic characteristics.

CONCLUSIONS

EGFR is expressed in a subset of urinary bladder small cell carcinomas; however, expression of EGFR does not correlate with clinicopathologic variables. At the molecular level, EGFR overexpression in small cell carcinoma of the urinary bladder does not seem to be caused by gene amplification. The expression of EGFR raises the possibility that EGFR may be a potential therapeutic target in the treatment of this malignancy.

Extrapulmonary Small Cell Carcinoma of the Bladder

Among the many sites for primary small cell cancer is the genitourinary system. The majority of cases have been observed in the bladder and prostate. Small cell carcinoma accounts for less than 1% of all bladder tumors. Definitive predisposing factors are unknown; however, small cell carcinoma of the bladder has been associated with cigarette smoking, long-standing cystitis, bladder calculus, and augmented cystoplasty. Contrary to the early theory of derivation from Kulchitsky cells, it is now believed that small cell carcinoma of the bladder originates from the totipotent stem cells present in the submucosa of the bladder wall. A number of chromosomal aberrations have been reported in small cell cancer of the bladder. There are no specific clinical features that differentiate these patients from transitional cell carcinoma of the bladder; however, some patients may have associated paraneoplastic conditions. Diagnosis is established by cystoscopic-assisted biopsy. Like small cell carcinoma of the lung, small cell carcinoma of the bladder has a propensity for early metastases. There is no standard therapy for small cell carcinoma of the bladder and the prognosis is poor; however, patients treated with cisplatin-based chemotherapy regimens seem to have a better prognosis.

Clinical review – Small cell carcinoma of the bladder

OBJECTIVES

To review the published literature on the diagnosis and management of small cell carcinoma of the bladder (SCCB).

METHODS

Papers were identified by searches of PubMed using the terms "small cell", "bladder" and "carcinoma". Additional papers were identified from review of references of relevant articles.

RESULTS

SCCB comprises less than 1% of bladder malignancies. It is an aggressive tumour that commonly presents at an advanced stage, in an elderly population. Consequently, patients are often not fit for anti-neoplastic therapy. In fit patients, the bedrock of treatment in the majority of cases is platinum-based systemic chemotherapy, which was the only factor predictive of improved outcome on multivariate analysis in one large review. The use of neoadjuvant chemotherapy has been associated with favourable results and may therefore be the preferred approach when scheduling treatment. Options for local management comprise surgery or radiotherapy (sequentially or concurrently with chemotherapy), both of which are potentially curative in selected cases. However, the subsequent frequent development of urothelial malignancies with bladder-sparing approaches should be considered when planning treatment, particularly in younger patients. Prognosis of SCCB overall is poor, the median survival of all cases varies from 4 to 23 months, and overall survival at 5 years from 10% to 40% of patients.

CONCLUSIONS

SCCB is a rare and aggressive tumour with a poor prognosis. Future efforts should be directed at its early detection and the development of more effective systemic therapies.

Role of E2F3 expression in modulating cellular proliferation rate in human bladder and prostate cancer cells

Amplification and overexpression of the E2F3 gene at 6p22 in human bladder cancer is associated with increased tumour stage, grade and proliferation index, and in prostate cancer E2F3 overexpression is linked to tumour aggressiveness. We first used small interfering RNA technology to confirm the potential importance of E2F3 overexpression in bladder cancer development. Knockdown of E2F3 expression in bladder cells containing the 6p22 amplicon strongly reduced the extent of bromodeoxyuridine (BrdU) incorporation and the rate of cellular proliferation. In contrast, knockdown of CDKAL1/FLJ20342, another proposed oncogene, from this amplicon had no effect. Expression cDNA microarray analysis on bladder cancer cells following E2F3 knockdown was then used to identify genes regulated by E2F3, leading to the identification of known E2F3 targets such as Cyclin A and CDC2 and novel targets including pituitary tumour transforming gene 1, Polo-like kinase 1 (PLK1) and Caveolin-2. For both bladder and prostate cancer, we have proposed that E2F3 protein overexpression may cooperate with removal of the E2F inhibitor retinoblastoma tumor suppressor protein (pRB) to drive cellular proliferation. In support of this model, we found that ectopic expression of E2F3a enhanced the BrdU incorporation, a marker of cellular proliferation rate, of prostate cancer DU145 cells, which lack pRB, but had no effect on the proliferation rate of PC3 prostate cancer cells that express wild-type pRB. BrdU incorporation in PC3 cells could, however, be increased by overexpressing E2F3a in cells depleted of pRB. When taken together, these observations indicate that E2F3 levels have a critical role in modifying cellular proliferation rate in human bladder and prostate cancer.

Chromosome 6p amplification and cancer progression

Chromosomal imbalances represent an important mechanism in cancer progression. A clear association between DNA copy-number aberrations and prognosis has been found in a variety of tumours. Comparative genomic hybridisation studies have detected copy-number increases affecting chromosome 6p in several types of cancer. A systematic analysis of large tumour cohorts is required to identify genomic imbalances of 6p that correlate with a distinct clinical feature of disease progression. Recent findings suggest that a central part of the short arm of chromosome 6p harbours one or more oncogenes directly involved in tumour progression. Gains at 6p have been associated with advanced or metastatic disease, poor prognosis, venous invasion in bladder, colorectal, ovarian and hepatocellular carcinomas. Copy number gains of 6p DNA have been described in a series of patients who presented initially with follicle centre lymphoma, which subsequently transformed to diffuse large B cell lymphoma. Melanoma cytogenetics has consistently identified aberrations of chromosome 6, and a correlation with lower overall survival has been described. Most of the changes observed in tumours to date map to the 6p21-p23 region, which encompasses approximately half of the genes on all of chromosome 6 and one third of the number of CpG islands in this chromosome. Analyses of the genes that cluster to the commonly amplified regions of chromosome 6p have helped to identify a small number of molecular pathways that become deregulated during tumour progression in diverse tumour types. Such pathways offer promise for new treatments in the future.

[Small cell carcinoma of the urinary bladder in a young man. A case report and literature review]

Small cell carcinoma of the bladder is a rare entity characterized by an aggressive clinical behaviour with a high incidence of systemic metastases. We report a case of small cell carcinoma of the bladder in a young man. The primary local tumour was treated by radical surgery, pelvic radiation therapy and polychemotherapy according CDDP protocol. The patient died six months after surgery because disease progression. We also review and update the literature concerning this infrequently tumour.

Chromosomal changes in uroepithelial carcinomas

This article reviews and summarizes chromosomal changes responsible for the initiation and progression of uroepithelial carcinomas. Characterization of these alterations may lead to a better understanding of the genetic mechanisms and open the door for molecular markers that can be used for better diagnosis and prognosis of the disease. Such information might even help in designing new therapeutic strategies geared towards prevention of tumor recurrences and more aggressive approach in progression-prone cases.

The revision of 205 cases of uroepithelial carcinomas reported with abnormal karyotypes showed karyotypic profile characterized by nonrandom chromosomal aberrations varying from one or few changes in low-grade and early stage tumors to massively rearranged karyotypes in muscle invasive ones. In general, the karyotypic profile was dominated by losses of chromosomal material seen as loss of entire chromosome and/or deletions of genetic materials. Rearrangements of chromosome 9 resulting in loss of material from 9p, 9q, or of the entire chromosome were the most frequent cytogenetic alterations, seen in 45% of the cases. Whereas loss of material from chromosome arms 1p, 8p, and 11p, and gains of chromosome 7, and chromosome arm 1q, and 8q seem to be an early, but secondary, changes appearing in superficial and well differentiated tumors, the formation of an isochromosome for 5p and loss of material from 17p are associated with more aggressive tumor phenotypes. Upper urinary tract TCCs have identical karyotypic profile to that of bladder TCCs, indicating the same pathogenetic mechanisms are at work in both locales. Intratumor cytogenetic heterogeneity was not seen except in a few post-radiation uroepithelial carcinomas in which distinct karyotypic and clonal pattern were characterized by massive intratumor heterogeneity (cytogenetic polyclonality) with near-diploid clones and simple balanced and/or unbalanced translocations. In the vast majority of cases strong correlation between the tumors grade/stage and karyotypic complexity was seen, indicating that progressive accumulation of acquired genetic alterations is the driving force behind multistep bladder TCC carcinogenesis. Although most of these cytogenetic alterations have been identified for many years, the molecular consequences and relevant cancer genes of these alterations have not yet been identified. However, loss of TSG(s) from chromosome 9 seems to be the primary and important event(s) in uroepithelial carcinogenesis

E2F3 amplification and overexpression is associated with invasive tumor growth and rapid tumor cell proliferation in urinary bladder cancer

E2F3 is located in the 6p22 bladder amplicon and encodes a transcription factor important for cell cycle regulation and DNA replication. To further investigate the role of E2F3 in bladder cancer, a tissue microarray containing samples from 2317 bladder tumors was used for gene copy number and expression analysis by means of fluorescence in situ hybridization (FISH) and immunohistochemistry (IHC). E2F3 amplification was strongly associated with invasive tumor phenotype and high tumor grade (P < 0.0001 each). None of 272 pTaG1/G2 tumors, but 35 of 311 pT1-4 carcinomas (11.3%), had E2F3 amplification. A high E2F3 expression level was associated with high grade, advanced stage, and E2F3 gene amplification (P < 0.0001 each). To evaluate whether E2F3 expression correlates with tumor proliferation, the Ki67 labeling index (LI) was analysed for each tumor. There was a strong association between a high Ki67 LI and E2F3 expression (P < 0.0001), which was independent of grade and stage. We conclude that E2F3 is frequently amplified and overexpressed in invasively growing bladder cancer (stage pT1-4). E2F3 expression appears to provide a growth advantage to tumor cells by activating cell proliferation in a subset of bladder tumors.

Small-cell carcinoma of the urinary bladder. A clinico-pathological study of ten cases

Small-cell carcinoma (SCC) of the urinary bladder is an infrequent neoplasia accounting for 0.5% of all tumors located at this level. There is a predilection for males over females with a 4:1 proportion and a median age of 66 years. In most cases, the initial diagnosis is made at the metastatic or progressive stage of the disease. For this study, we collected ten cases of SCC of the urinary bladder, diagnosed over a period of 16 years, to describe the morphological and immunocytochemical characteristics of these infrequent neoplasia. In all cases, clinical data such as age at presentation, personal background, clinical symptoms, stage, treatment, clinical outcome and present status were available. Primary antibodies included chromogranin, neuron-specific enolase, synaptophysin, PGP 9.5, HNK-1, cytokeratin 34betaE12, cytokeratin 20, thyroid transcription factor-1 (TTF-1), c-erbB2 (CB-11), p53 (DO7), and Ki67 (MIB-1). In addition to the expression of neural/neuroendocrine markers, immunostaining for p53 and c-erbB2 was found in 80% and 50% of cases, respectively. In this paper, we confirm the aggressive course of the neoplastic disease. The expression of c-erbB2 in 50% of cases opens up hypothetical new possibilities for the use of immunotherapy in such cases.

Amplification and overexpression of E2F3 in human bladder cancer

We demonstrate that, in human bladder cancer, amplification of the E2F3 gene, located at 6p22, is associated with overexpression of its encoded mRNA transcripts and high levels of expression of E2F3 protein. Immunohistochemical analyses of E2F3 protein levels have established that around one-third (33/101) of primary transitional cell carcinomas of the bladder overexpress nuclear E2F3 protein, with the proportion of tumours containing overexpressed nuclear E2F3 increasing with tumour stage and grade. When considered together with the established role of E2F3 in cell cycle progression, these results suggest that the E2F3 gene represents a candidate bladder cancer oncogene that is activated by DNA amplification and overexpression.

Small-cell neuroendocrine carcinoma displays unique profiles of tumor-suppressor gene loss in relationship to the primary site of formation

Small-cell neuroendocrine carcinoma (SCNC) is a well characterized malignancy with distinctive cellular morphology and aggressive biologic behavior most frequently encountered in the lung but also noted for origin from other sites. The basis for this difference in incidence and the impact of primary site location on the molecular pathogenesis of the neoplasm is not well understood. To address this issue and to identify reliable molecular markers of potential diagnostic value for primary site localization of this tumor, we have compared the genetic profile of cancer-related gene damage of SCNC arising from a variety of organ sites. The analysis involved microdissected paraffin-embedded formalin fixed specimens of SCNC. Tumors were organized into 3 groups: lung (n = 18), head and neck region (n = 5), and gastrointestinal tract (n = 5). Genotyping evaluated allelic imbalance (loss of heterozygosity) involving genomic regions containing p53 (17p13), L-myc (1p34), OGG1 (3p26), MCC/APC (5q21), p16 (9p21), PTEN (10q23), and point mutational change in K-ras-2 (12p12) using polymerase chain reaction-based microsatellite analysis and DNA sequencing. Distinct genotypic profiles of allelic imbalance using this panel was seen for each group of SCNC enabling primary site determination to be suggested based on genotypic profiling of microdissected tissue samples. Despite similarity in histologic appearance, our study suggests that SCNC have a unique pattern of acquired allelic damage that is determined in part by primary site of tumor development. These attributes can be effectively used for primary localization of metastatic SCNC, thereby assisting in the diagnosis and classification of this neoplasm.

Compilation of published comparative genomic hybridization studies

The power of comparative genomic hybridization (CGH) has been clearly proven since the first paper appeared in 1992 as a tool to characterize chromosomal imbalances in neoplasias. This review summarizes the chromosomal imbalances detected by CGH in solid tumors and in hemopathies. In May of 2001, we took a census of 430 articles providing information on 11,984 cases of human solid tumors or hematologic malignancies. Comparative generic hybridization has detected a number of recurrent regions of amplification or deletion that allows for identification of new chromosomal loci (oncogenes, tumor suppressor genes, or other genes) involved in the development, progression, and clonal evolution of tumors. When CGH data from different studies are combined, a pattern of nonrandom genetic aberrations appears. As expected, some of these gains and losses are common to different types of pathologies, while others are more tumor-specific.

Chromosomal aberrations in benign and malignant bilharzia-associated bladder lesions analyzed by comparative genomic hybridization

BACKGROUND

Bilharzia-associated bladder cancer (BAC) is a major health problem in countries where urinary schistosomiasis is endemic. Characterization of the genetic alterations in this cancer might enhance our understanding of the pathogenic mechanisms of the disease but, in contrast to nonbilharzia bladder cancer, BAC has rarely been the object of such scrutiny. In the present study, we aimed to characterize chromosomal imbalances in benign and malignant post-bilharzial lesions, and to determine whether their unique etiology yields a distinct cytogenetic profile as compared to chemically induced bladder tumors.

METHODS

DNAs from 20 archival paraffin-embedded post-bilharzial bladder lesions (6 benign and 14 malignant) obtained from Sudanese patients (12 males and 8 females) with a history of urinary bilharziasis were investigated for chromosomal imbalances using comparative genomic hybridization (CGH). Subsequent FISH analysis with pericentromeric probes was performed on paraffin sections of the same cases to confirm the CGH results.

RESULTS

Seven of the 20 lesions (6 carcinomas and one granuloma) showed chromosomal imbalances varying from 1 to 6 changes. The most common chromosomal imbalances detected were losses of 1p21-31, 8p21-pter, and 9p and gain of 19p material, seen in three cases each, including the benign lesion.

CONCLUSION

Most of the detected imbalances have been repeatedly reported in non-bilharzial bladder carcinomas, suggesting that the cytogenetic profiles of chemical- and bilharzia-induced carcinomas are largely similar. However, loss of 9p seems to be more ubiquitous in BAC than in bladder cancer in industrialized countries.

High-throughput tissue microarray analysis of cyclin E gene amplification and overexpression in urinary bladder cancer

Studies by comparative genomic hybridization revealed that the 19q13 chromosomal region is frequently amplified in bladder cancer. The cyclin E gene (CCNE), coding for a regulatory subunit of cyclin-dependent kinase 2, has been mapped to 19q13. To investigate the role of cyclin E alterations in bladder cancer, a tissue microarray of 2,317 specimens from 1,842 bladder cancer patients was constructed and analyzed for CCNE amplification by fluorescence in situ hybridization and for cyclin-E protein overexpression by immunohistochemistry. Fluorescence in situ hybridization analysis showed amplification in only 30 of the 1,561 evaluable tumors (1.9%). Amplification was significantly associated with stage and grade (P: < 0.0005 each). Immunohistochemically detectable cyclin E expression was strong in 233 (12.4%), weak in 354 (18.9%), and negative in 1, 286 of the 1,873 interpretable tumors. The majority (62.1%) of CCNE-amplified tumors were strongly immunohistochemistry-positive (P: < 0.0001). The frequency of protein expression increased from stage pTa (22.2%) to pT1 (45.5%; P: < 0.0001) but then decreased for stage pT2-4 (29.4%; P: < 0.0001 for pT1 versus pT2-4). Low cyclin E expression was associated with poor overall survival in all patients (P: < 0.0001), but had no prognostic impact independent of stage. It is concluded that cyclin E overexpression is characteristic to a subset of bladder carcinomas, especially at the stage of early invasion. This analysis of the prognostic impact of CCNE gene amplification and protein expression in >1,500 arrayed bladder cancers was accomplished in a period of 2 weeks, illustrating how the tissue microarray technology remarkably facilitates the evaluation of the clinical relevance of molecular alterations in cancer.