Metastatic small cell bladder cancer treated with sequential systemic therapy including pembrolizumab and amrubicin: A case report

Abstract

Introduction Small cell bladder cancer is a relatively rare tumor, representing <1% of all bladder tumors. Amrubicin monotherapy is used as second‐line treatment for small cell lung cancer in Japan. Case presentation A 79‐year‐old woman presented with gross hematuria and was diagnosed with small cell bladder cancer (T2 or higher). Neoadjuvant chemotherapy with etoposide and cisplatin resulted in a partial response. Robot‐assisted radical cystectomy was performed, and radical resection was achieved. As we identified metastasis in the pleura 1 year later, we administered carboplatin and etoposide, which resulted in a partial response. Although pembrolizumab was initiated as maintenance therapy, it was not effective. Amrubicin was given as third‐line therapy, and stable disease was achieved without serious adverse effect for 6 months. Conclusion Although there is no established treatment for metastatic small cell bladder cancer, the current case report suggests the effectiveness of amrubicin in this setting.

Keywords

• amrubicin
• immune checkpoint inhibitors
• small cell bladder cancer