The Role of Immune Checkpoint Inhibitors in the Treatment of Extensive-Stage Extrapulmonary Small Cell Carcinoma

Small cell carcinoma is a type of highly aggressive poorly differentiated neuroendocrine tumor that can arise from multiple organs, including but not limited to bronchial tissue, pancreas, gastrointestinal tract, and genitourinary system. The most commonly studied type is small cell lung cancer (SCLC) which carries the worst prognosis among lung cancers. After multiple promising clinical trials, the National Comprehensive Cancer Network has recently added atezolizumab and durvalumab in combination with platinum-based chemotherapy/etoposide to the first-line treatment regimen for extensive-stage SCLC (ES-SCLC). Meanwhile, the recommended treatment for extrapulmonary small cell carcinoma (EPSCC) remains unchanged. In this review, we try to explore the role of immunotherapy in the treatment of EPSCC.