An evidence mapping and scientometric analysis of the top-100 most cited clinical trials of anti-PD-1/PD-L1 drugs to treat cancers

Objective: To gain a deeper understanding of the hot topics and future prospects of programmed cell death 1 (PD1)/programmed cell death ligand 1 (PD-L1) inhibitors treatment of cancer through scientometric analysis of the top-100 most cited clinical trials. Materials and methods: We searched the Web of Science Core Collection database from 1980 to June 2019. Two reviewers independently screened the top-100 most cited clinical trials that defined by the National Institutes of Health starting from the most cited article. Title, year of publication, citations, type of cancer, and focused aspects of outcomes were extracted from included clinical trials. VOSviewer software (version 1.6.9) and Excel 2016 were used to do statistical analysis. The evidence mapping was used to present the relationship between cancers, drugs, citations, and outcomes, etc. Results: The top-100 most cited clinical trials published from 2010 to 2018 in nine journals with high impact factor (IF) (IF2018:6.68-70.67), and Lancet Oncology (USA) published the most clinical trials (n = 29, IF2018 = 35.3856). The total number of citations of the top-100 most cited clinical trials was from 59 to 5606. 920 authors from 34 countries and 458 organizations participated in publishing the top-100 most cited clinical trials. The USA (n = 95) and Memorial Sloan-Kettering Cancer Center (n = 31) contributed the most publications. Based on the evidence mapping, there are 25 different types of cancers (e.g. lung cancer, melanoma, and renal cell cancer) and five focused aspects of outcomes (e.g. safety and efficacy). Conclusion: The USA was the dominant country. Anti-PD-1/PD-L1 drugs were widely used to treat lung cancer, melanoma, renal cell cancer, and Hodgkin lymphoma. More exploration should be done to explore the use of anti-PD-1/PD-L1 drugs to treat more type of cancers in future research.