Mapping the evolution of immune checkpoint inhibitor research in small cell lung cancer: A bibliometric analysis (1997–2025)

Immune checkpoint inhibitors (ICIs) have revolutionized small cell lung cancer (SCLC) treatment, yet a comprehensive bibliometric analysis of global research trends is lacking. This study examines publication patterns, key contributors, and emerging research focuses on ICIs in SCLC using bibliometric tools. We analyzed 809 articles from the Web of Science Core Collection (1997–2025) with VOSviewer, CiteSpace, and Bibliometrix. Publications grew at 9.11% annually, with China (304 articles), the USA (201), and Japan (101) as top contributors. Leading institutions included the University of Texas System (105 articles) and UTMD Anderson Cancer Center (84). Frontiers in Oncology (38 articles) and Thoracic Cancer (32) were prominent journals. Key researchers were Wang J (21 articles, 1,706 citations) and Reck M (15 articles, 4,341 citations). Keyword analysis identified four clusters: (1) ICI mechanisms and immune-related molecules, (2) chemotherapy combinations, (3) clinical trial designs, and (4) ICI efficacy/safety. Burst terms included overall survival, radiation therapy, and placebo. Emerging trends highlight multimodal strategies, ICI-radiation synergy, and open-label trials. Research hotspots focus on ICI mechanisms, combination therapies, trial optimization, and safety. Future directions should explore predictive biomarkers, novel combinations, and tailored protocols to improve SCLC outcomes. This study provides a roadmap for advancing ICI research in SCLC, emphasizing global collaboration and translational innovation.