[Expert consensus on immunotherapy for small cell lung cancer (2025 edition)]

Lung cancer is one of the malignant tumors with high morbidity and mortality worldwide. Small cell lung cancer (SCLC) is a highly aggressive neuroendocrine tumor that is closely associated with tobacco exposure, accounting for 13% to 15% of all lung cancer cases. It is characterized by a high proliferation rate and exceptional metastatic capacity. At the time of diagnosis, approximately 70% of the patients have metastasized and are classified as extensive-stage small cell lung cancer (ES-SCLC). From 1980 to 2018, chemotherapy and radiotherapy were the main treatment strategies for SCLC. Etoposide combined with platinum has remained the standard first-line treatment for ES-SCLC. Although SCLC is very sensitive to initial treatment, the majority of patients have disease progression within 6 months, and treatment options after recurrence are very limited, and the median survival time is only about 8-10 months. The advent of immune checkpoint inhibitors (ICIs), particularly programmed death-ligand 1 (PD-L1) and programmed death -1 (PD-1) inhibitors, has brought new hope to patients with SCLC. PD-1/PD-L1 plus chemotherapy have significantly prolonged overall survival of patients with ES-SCLC, which has become the new standard of first-line treatment for ES-SCLC. Currently, a raised number of immune checkpoint inhibitors (ICIs) have been approved in China for the treatment of SCLC, providing more treatment options for SCLC patients. To further standardize the clinical practice of SCLC immunotherapy, the "Expert consensus on immunotherapy for SCLC (2025 edition)" has been developed based on domestic and international guidelines, consensus, and relevant medical evidence, aiming to provide reference and guidance for domestic clinicians.