Single-Institution Experience Of Small Cell Bladder Cancer At A Community Center.

e17021 Background: Small cell bladder cancer (SCBC) is a rare malignancy with poor prognosis. Previous retrospective studies mainly focused on answering whether radical cystectomy is superior to radiation. Little is known about the disease characteristics and clinical course. Methods: Patients were identified via Geisinger cancer registry from 1991 to 2019, and retrospective chart review was performed through the electronic health records, EPIC. We described patient characteristics and outcomes. OS was measured from time of initial diagnosis to death or last follow up. Kaplan-Meier analyses were done on OS. Results: 50 patients were identified; 7 patients were excluded due lack of information. M: F≈1, 60% patients had pure small cell carcinoma (SCC) histology (≥ 95%), 37% with SCC and urothelial carcinoma mixed histology, MIB-1 index was 80-100%. Median OS for localized disease (IQR) was 22 months (9,73), and 11 months (7,16) for metastatic disease. For localized disease, OS were similar between patients with or without pure small cell history (P = 0.47). 8 patients were alive at 5 years; 3 patients received neoadjuvant chemotherapy followed by radical cystectomy, 2 patients underwent radical cystectomy alone, 2 patients had concurrent chemotherapy with radiation; 1 patient had complete pathological response to Cisplatin and etoposide chemotherapy, did not receive additional therapy and recurred 6 years later. Recurrence ranged from 6 to 79 months. 10 patients had disease progression despite of palliative chemotherapy. Conclusions: Small cell bladder cancer is a heterogenous disease, early stage disease can be curable but late recurrence does occur, continued surveillance is warranted even after 5 years. New treatment modality is in need to improve outcome for patients with metastatic disease.