Neuroendocrine carcinoma of the urinary bladder (NCUB): a large, retrospective study from the French Genito-Urinary Tumor Group (GETUG)

Abstract Background Neuroendocrine carcinoma of the urinary bladder (NCUB) accounts for less than 1% of bladder cancers, published data is scarce. Methods We, retrospectively, reviewed cases of NCUB patients from French institutions. The objectives were to describe patients’ characteristics, treatments received, outcomes (disease-free survival (DFS), progression-free survival (PFS), overall survival (OS)) and investigate prognostic factors. Results From 1997 to 2017, we included 236 patients, 173 with early stage NCUB and 63 with advanced stage. At early stage disease, median DFS was better in patients who received cisplatin-based chemotherapy compared to carboplatin (HR=1.95; CI 95%, 1.1-3.46), there was no difference between neoadjuvant and adjuvant setting (HR=1.1; 0.61-1.97). Median OS (mOS) was 36 months (29-43) for stages I and II, 26 months (18-NR) for stage IIIA, 16 months (CI95%, 12-21) for stage IIIB, HR for IIIB compared to I/II = 2.6 (1.5-4.4). DFS at 6 months was associated to OS, HR=7.8 (4.1-15.0). In metastatic patients at diagnosis who received chemotherapy, median PFS was 9 months (8-11) for first-line cisplatin and 6 months (4-13) for carboplatin, mOS was 13 months (9-15). A high-risk Bajorin score (HR = 11.5; 1.2-112.6) and the use of carboplatin (HR = 2.26; 1.03-4.96) were associated to worse outcomes. Conclusions At early stage disease, a shorter DFS was associated with worse OS, the use of cisplatin was associated with better OS. In patients with metastases at diagnosis, a high risk Bajorin’s score and the use of carboplatin were associated with worse outcomes.