Neuroendocrine carcinoma of the urinary bladder. 15-year retrospective analysis.

Objectives: Neuroendocrine tumors (NET) are cancers found in the bronchopulmonary tract, where they were first described in 1926. The tumors are associated with poor prognosis due to their high metastatic potency even after radical treatments associated with other neo- or adjuvant therapies. NET of the urinary bladder is a rare tumor and accounts for 0.5% of bladder tumors.

Methods: The study was designed as an observational, descriptive and retrospective study of 13 patients diagnosed, treated, and followed for NET of the urinary bladder at the Hospital and University Complex of Albacete, Albacete, Spain between 1995 and 2010.

Results: The sample was composed of 11 men and 2 women. Mean patient age at the time of diagnosis was 71 (range, 57-88; SD, 6.98) years. T4 (6 patients) was the most common T tumor stage, followed by T2 (5 patients) and T3 (2 patients). In the case of N tumor stage, the most common was N2. In the remaining 3 patients, the degree of lymph node involvement could not be assessed. Six presented distant metastasis at the time of diagnosis. Eleven patients presented small-cell NET on histology. Seven underwent radical surgery (radical cystectomy). All other patients were treated by deep transurethral resection of bladder tumor, except for 1 patient treated by partial cystectomy. Adjuvant chemo-therapy (usually an association of carboplatin/cisplatin and etoposide) was administered to 4 patients. Of these 4 patients, 2 were also treated by pelvic radiotherapy. Two patients survived more than 5 years following diagnosis. In fact, at the time the study data was collected only 4 patients had survived and 2 presented tumor recurrence. Of the 9 deaths, 8 occurred within 6 months of diagnosis and 1 at 24 months. All of them were the result of the disease itself.

Conclusions: Neuroendocrine tumor of the urinary bladder is a rare, aggressive tumor with high metastatic potential that should be considered in the differential diagnosis of urinary bladder neoplasms. Despite various multimodality treatments have been used prognosis is poor.