BACKGROUND: Small cell lung cancer (SCLC) is initially highly sensitive to chemotherapy, which often leads to significant tumor reduction. However, the majority of patients eventually develop resistance, and the disease is further complicated by its “cold” tumor microenvironment, characterized by low tumor immunogenicity and limited CD8+ T cell infiltration. These factors contribute to the poor response to immunotherapy in many cases of extensive-stage SCLC (ES-SCLC). High-dose chemotherapy …