Analysis Of Clinicopathological Characteristics And Prognostic Factors Of Bladder Neuroendocrine Carcinomas Based On A SEER Database

Background: Bladder neuroendocrine carcinomas(BNEC)are a relatively rare type of tumor,which account for less than 1% of all the bladder carcinomas.It varies from carcinoid tumor to more aggressive small cell carcinoma.The clinicopathological characteristics,predictors and treatment plans of such tumor are matters of dispute due to its rarity.The aim of this studys to examine the clinicopathological characteristics and predictors of survival outcomes of patients with bladder neuroendocrine carcinomas based on the analysis of the national Surveillance,Epidemiology,and End Results(SEER)database,which is of great significance.Sources and methods: BNEC are divided into small cell neuroendocrine carcinoma(SCNEC),large cell neuroendocrine carcinoma(LCNEC),well-differentiated neuroendocrine tumor(carcinoid tumor)and paraganglioma(PGL).In this study,the clinic and pathologic data,of 905 patients suffering from primary BNEC between 2004 to 2014,was investigated and reviewed.Cross-list analysis was applied to display the diversity,while the Kaplan–Meier analysis with log-rank test was used for survival comparisons,including cancer-specific survival(CSS)and overall survival(OS).According to the survival table,the CSS and OS of 1 year,3 years,5 years,and 10 years under different treatment plans after the diagnosis of the patient are calculated.Multivariate Cox regression model was employed to analyze the effect of different treatments on OS and CSS,to make the existing prognosis of BNEC clear.Result: Among all 905 cases,648(71.6%)were SCNEC;35(3.9%)were LCNEC;carcinoid tumor is least-10(1.1%);PGL are 10 cases(1.2%)and 214 patients(1.8%)are neuroendocrine carcinomas,NOS(not otherwise specified).In detail,SCNEC,LCNEC and neuroendocrine carcinomas,occupying overall 97.9%,virtually all the patients,are commonly seen in males aged more than 60 in lateral wall of bladder.These three poorly differentiated or undifferentiated carcinomas,more than 2cm in diameter,are more of muscle-invasive bladder cancer and less of arising regional lymph node metastasis and distant metastasis.However,carcinoid tumor and PGL occur exclusively in 60-year-older male patients,and they are well-differentiated and moderately differentiated in normal.American Joint Committee on Cancer(AJCC)TNM is uncapable of periodization with diameter of less than 5cm.Using multivariable Cox proportional hazard model,age,histology,N stage,SEER stage,tumor size,radiotherapy,chemotherapy and local treatment of the primary site are identified as independent predictors for OS and CSS.Compared with SCNEC and LCNEC,carcinoid tumor and PGL have a superiority in existing predictors,which in every hypo-type tumor generally get worse with increasing age and carcinomas size.The prognosis of cystectomy in the primary site is better than local tumor resection and no surgical treatment.Patients receiving chemotherapy and radiotherapy have a better prognosis.As for combination therapy,the median CSS time of cystectomy + chemotherapy + radiotherapy group,cystectomy + chemotherapy group,tumor resection + chemotherapy + radiotherapy group is 108.00 months,49.07 months and 33.77 months respectively,56%?61% and 59% separately for one-year CSS,56%?50% and 42% for three-year CSS,556%?48% and 40% for five-year CSS and 56%?48% and 0 for ten-year CSS;the median OS time is 88.00 months,31.39 months and 25.42 months respectively,56%?57% and 51% separately for one-year OS,56%?45% and 37% for three-year OS,56%?43% and 29% for five-year OS and 0?31% and 0 for ten-year OS.Conclusion: In BNEC,SCNEC are in the absolute majority while both carcinoid tumor and PGL are rare cases.Clinical pathology of LCNEC and SCNEC is similar,and they have the same similarity in therapy and predictors.Otherwise,patients with PGL and consequently carcinoid tumors have better prognosis than LCNEC and SCNEC.For treatment,there is high survival time for all three combination therapies,in which cystectomy + chemotherapy + radiotherapy should be a major component of treatment because of its highest CSS.Nevertheless,chemotherapy shall not to be ignored since it is essential adjuvant therapy.