Methods: A bibliometric analysis was conducted using publications retrieved from the Web of Science Core Collection on March 15, 2026. Eligible studies were limited to English-language articles and reviews published till 2025. Records unrelated to LLMs or cancer, duplicates, retracted publications, and those missing complete metadata were excluded. A total of 896 publications were analyzed using VOSviewer, CiteSpace, and R. ClinicalTrials.gov was searched with the same term, obtaining 29 eligible trials. 

 Results: Publication output increased sharply from 2022 to 2025. The USA and China dominated global output, with Germany demonstrating disproportionate citation efficiency relative to volume, and Heidelberg University and Harvard University leading institutionally. Research hotspots converged on LLM benchmarking, domain-specific fine-tuning, multi-omics integration, and perioperative applications. Among 29 registered trials, application areas spanned patient communication, shared decision-making, and care equity outcomes, reflecting a transition from proof-of-concept toward randomized evaluation. 

 Conclusions: LLM-driven oncology research has expanded rapidly but remains geographically and institutionally concentrated, with prospective multicenter validation still scarce. Research is transitioning from foundational benchmarking toward fine-tuning, multimodal integration, and clinical deployment. Strengthening cross-institutional collaboration, diversifying trial populations, and developing standardized safety evaluation frameworks are essential for translating bibliometric growth into meaningful advances in cancer diagnosis, treatment, and patient outcomes.