Global research trends on biomarkers for cancer immunotherapy: Visualization and bibliometric analysis

The global burden of cancer continues to grow, posing a significant public health challenge. Although cancer immunotherapy has shown significant efficacy, the response rate is not high. Therefore, the objective of our research was to identify the latest research trends and hotspots on biomarkers from 1993 to 2023. Data were collected from the database Web of Science core collection. Bibliometric analysis and visualization were conducted with CiteSpace(6.3.1), VOSviewer (v1.6.20), R-bibliometrix(v4.3.3), and Microsoft Excel(2019). A total of 2686 literatures were retrieved. The sheer annual volume of publications has shown a rapid upward trend since 2015. The United States has generated the most publications and Harvard University ranked as a leading institution. The global biomarker research on immune checkpoint inhibitors (ICIs) revealed regional differences and in-depth explorations should be promoted in developing countries. Although China has become the second largest country in terms of publication, the average citation per paper and the total link strength were both lower than the other countries. The research on biomarkers mainly concentrated upon the following aspects: PD-1/PD-L1, CTLA-4, gene expression, adverse events, total mutational burden (TMB), body mass index (BMI), gut microbiota, cd8(+)/cd4(+) t-cells, and blood-related biomarkers such as lactate dehydrogenase (LDH), neutrophil-lymphocyte ratio (NLR), cytokines. Furthermore, "artificial intelligence" and "machine learning" have become the most important research hotspot over the last 2 y, which will help us to identify useful biomarkers from complex big data and provide a basis for precise medicine for malignant tumors.