Small cell bladder carcinoma treated with nivolumab as adjuvant maintenance therapy.

We report using the programmed death-1 immune checkpoint inhibitor (ICI) antibody, nivolumab, as part of a multimodal treatment strategy in small cell bladder carcinoma (SCBC). The patient presented with gross haematuria and was diagnosed with urothelial carcinoma with SCBC. He received neoadjuvant chemotherapy (NAC; carboplatin plus etoposide) according to the small cell lung cancer regimen. After three cycles of NAC, there was no progression of local disease, and a robot-assisted radical cystectomy with ileal conduit was conducted. Post surgery, the patient was treated with nivolumab (240 mg) every 2 weeks as a maintenance therapy after adjuvant cisplatin plus etoposide therapy. After more than 1.5 years post surgery, no tumour recurrence or metastases are present. The patient was treated with nivolumab, which was curative after radical cystectomy. Further research is required to elucidate the potential role of ICIs in SCBC.