Structural and temporal dynamics analysis of PD-1/PD-L1 immunotherapy in hepatocellular carcinoma: History, research hotspots, and emerging trends

This research aims to explore the historical evolution, key research areas, and new trends in PD-1/PD-L1 immunotherapy for hepatocellular carcinoma (HCC) over the last twenty years, focusing on structural and temporal dynamics. The Web of Science Core Collection (WoSCC) database was used to gather studies on PD-1/PD-L1 immunotherapy for HCC.CiteSpace and HistCite were utilized for a bibliometric analysis to investigate the historical progression, research evolution, and emerging trends in this area. In the last two decades, 2804 papers on PD-1/PD-L1 immunotherapy in HCC have been published, comprising 541 reviews and contributions from 13,796 authors across 2,659 institutions. Since 2014, the number of annual publications has significantly increased, with extensive international collaboration. Several active research topics have emerged, covering 72 disciplines, generating 561 keywords, and 1,199 articles that experienced citation bursts. Cluster analysis of keywords revealed five emerging subfields: lenvatinib, immune escape, immne checkpoint inhibitors, prognostic models, and tumor microenvironment. According to the "Timeline visualization of references," classic topics include CMTM6, regulatory T cells, liver transplantation, and bioinformatics analysis, while emerging topics include prognosis, lenvatinib, transarterial chemoembolization, hepatic arterial infusion chemotherapy, and single-cell RNA sequencing. This study sheds light on the current status and developing trends in PD-1/PD-L1 immunotherapy research for HCC, offering researchers valuable insights to identify crucial areas and explore new research directions.