Genitourinary small cell malignancies: prostate and bladder

Survival analysis of small cell carcinomas of the genitourinary system

Due to low incidence, there are no large prospective studies or clinical trials for small cell carcinoma (SCC) of the genitourinary system (GU), and most data are extrapolated from SCC of the lung. Using the SEER database, we analyzed incidence trends, overall survival, and cancer-specific survival using the log-rank test. Analysis of variables was performed using the Cox proportional hazards regression model. The analysis showed that SCC of the bladder and prostate were the most common types of GU SCC, with 1836 and 606 cases, respectively. In 2018, the incidence of SCC of the bladder and prostate was twice that of 2010 (P < 0.001). The overall survival and cancer-specific survival of patients with SCC of the bladder were significantly longer than those of patients with SCC of the prostate (P < 0.0001). SCC bladder patients with advanced age, more extensive growth, lymph node involvement, no surgical intervention, and the presence of the metastasis had worse survival outcomes (P < 0.05). The Asian/Pacific Islander race provided some survival benefits for patients with SCC of the bladder (P < 0.05). For patients with SCC of the prostate, only advanced age was a risk factor for poor outcomes (P < 0.05).

Clinical characteristics and survival of extrapulmonary small cell carcinoma in 11 different primary tumor sites in the United States, 1975-2016

OBJECTIVE

Few studies have investigated extrapulmonary small cell carcinoma (EPSCC) in a systematic way. This study is to analyze EPSCC in 11 tumor sites from different aspects in the United States (1975-2016).

METHODS

In total 4397 patients diagnosed with EPSCC in 11 primary tumor locations were selected from the Surveillance, Epidemiology and End Results (SEER) database. The incidence of EPSCC in the last decade, and the 1, 3 and 5 year survival rates of each tumor site were also roughly calculated. Prognostic factors of EPSCC were investigated by Cox regression analysis.

RESULTS

Statistically, the incidence of EPSCC was on the rise over the past 30 years. Of its 11 primary tumor sites, bladder was the most frequently affected while the stomach and kidney were rarely affected. Males were more susceptible to EPSCC than females. Married patients were more commonly afflicted by EPSCC, but had longer survival. Cases were most intensive in California and an increased trend had been observed. The 5 year overall survival (OS) rate ranged from 2.0% to 42.5% in patients with EPSCC in 11 tumor sites (p < .001). The OS was better for EPSCC in the breast and cervix. However, tumor sites in the colon, esophagus, pancreas, rectum and stomach were all associated with worse survival. Characteristics and prognosis of EPSCC in different tumor sites were statistically significant (p < .001). Age, gender, marital status, stage, surgery, radiotherapy and chemotherapy were equally significant factors of survival of EPSCC patients (p < .05).

CONCLUSION

There was an increasing trend of EPSCC incidence. The survival of EPSCC in different tumor sites was significantly different. Tumor locations, age, gender, marital status, stage, surgery, radiotherapy and chemotherapy were all important factors of survival. This study has implications for EPSCC prevention and treatment.

Clinicopathological characteristics and survival outcomes of bladder neuroendocrine carcinomas: a population-based study

Background

Bladder neuroendocrine carcinomas (BNECs) are relatively a rare type of tumor. The aim of this study was to examine the clinicopathological characteristics and predictors of survival outcomes of patients with BNECs based on the analysis of the national Surveillance, Epidemiology, and End Results (SEER) database.

Materials and methods

Kaplan-Meier analysis with log-rank test was used for survival comparisons. Multivariate Cox regression model was employed to analyze the effect of different treatments on overall survival (OS) and cancer-specific survival (CSS).

Results

A total of 910 patients were identified between 2004 and 2014. Overall, 648 (71.2%) patients had small cell neuroendocrine carcinoma (SCNEC), 35 (3.8%) had large cell neuroendocrine carcinoma (LCNEC), 10 (1.1%) had carcinoid tumor (well-differentiated neuroendocrine tumor), 16 (1.8%) had paraganglioma/pheochromocytoma (PGL/PHEO), 619 (68.0%) had a poorly differentiated or undifferentiated histology grade, 214 (23.5%) presented with metastatic disease, 586 (64.4%) underwent transurethral ablation/destruction for bladder tumor, and 245 (26.9%) had partial/total cystectomy. Cystectomy+chemotherapy+radiotherapy (CCR) has the highest long-term survival rate among various treatments. The 1-, 3-, and 5-years CSS of CCR were 56%, 56%, and 56%, respectively. By using multivariable Cox proportional hazard model, age, histology, N stage, SEER stage, tumor size, radiotherapy, chemotherapy, and local treatment of the primary site were identified as independent predictors for OS and CSS; all P<0.05.

Conclusion

In BNEC, SCNEC has an absolute advantage in number. SCNEC/LCNEC tend to be older men. PGL/PHEO and carcinoid tumors have younger mean ages, earlier tumor stages, and better prognosis than SCNEC/LCNEC. Surgery, radiotherapy and chemotherapy are better than conservative treatment. However, whatever cystectomy or bladder sparing, chemotherapy should be a major component of treatment.

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.

Cytomorphologic and Immunophenotypic Profile of a Cohort of Small Cell Carcinoma of the Urinary Bladder

BACKGROUND

The incidence of primary small cell carcinoma (SCC) of the urinary bladder is extremely rare. We sought to analyze the cytologic and immunophenotypic features of SCC of the urinary bladder in urine and reassert the importance of cytologic examination of urine specimens for diagnosis of this tumor.

METHODS

We studied the clinical and cytomorphologic features in the presurgical urine specimens (4 voided urine and 2 bladder-washing specimens) of histopathologically and immunohistochemically proven cases of SCC of the urinary bladder.

RESULTS

There were 6 cases, all males, with an age range of 61-81 years. On cytologic and histopathologic examination, typical SCC morphology was present in all cases. On immunohistochemistry, synaptophysin and CD56 were positive in all 6 cases, while chromogranin was positive in only 3. The Ki-67 labeling index ranged from 30 to 100%.

CONCLUSIONS

SCC should be kept in the differential diagnosis, when high-grade urothelial carcinoma is suspected in a urine cytology specimen, as this distinction has important therapeutic and prognostic implications. Therefore, a careful observation and, if required, the use of an appropriate immunocytochemical panel on the presurgical urine specimens can lead to a correct diagnosis.

Neuroendocrine Tumors of the Urinary Bladder According to the 2016 World Health Organization Classification: Molecular and Clinical Characteristics

Neuroendocrine neoplasms of the urinary bladder are a rare type of tumor that account for a small percentage of urinary bladder neoplasms. These tumors of the urinary bladder range from well-differentiated neuroendocrine neoplasms (carcinoids) to the more aggressive subtypes such as small cell carcinoma. Despite the rarity of the neuroendocrine tumors of the bladder, there has been substantial investigation into the underlying genomic, molecular, and the cellular alterations within this group of neoplasms. Accordingly, these findings are increasingly incorporated into the understanding of clinical aspects of these neoplasms. In this review, we provide an overview of recent literature related to the 2016 World Health Organization Classification of Neuroendocrine Tumors of the Urinary Bladder. Particular emphasis is placed on molecular alterations and recently described gene expression. The neuroendocrine tumors of the urinary bladder are subdivided into four subtypes. Similar to their pulmonary and other extrapulmonary site counterparts, these have different degrees of neuroendocrine differentiation and morphological features. The clinical aspects of four subtypes of neuroendocrine tumor are discussed with emphasis of the most recent developments in diagnosis, treatment, and prognosis. An understanding of molecular basis of neuroendocrine tumors will provide a base of knowledge for future investigations into this group of unusual bladder neoplasms.