A Brief Overview on Global Trends in Immunotherapy Research on Breast Cancer

The purpose of this study is to use bibliometric methods to analyze recent 10-year trends in immunotherapy research in breast cancer and consequently create a better under- standing of the current situation and trends of those research studies by analyzing their main characteristics. In recent years, many studies have focused on the host immune system and its relationship with tumor progression in a variety of solid tumors, including breast cancer. This study investigates recent trends of immunotherapy research in breast cancer and compares the contributions of research from different regions, institutions, and authors. A search of breast cancer and im- munotherapy studies that were published between 2010 and 2019—with different keyword combinations—was performed in the Web of Science database. Bibliometric data were collected for analysis. VOSviewer software was used to generate a figure for the keyword’s co-occurrence network, so as to implement network visualization analysis. A total of 1,041 publications were identified. The United States and China contributed to approximately 50% of the publications, 336 and 208, respectively. Both countries drove the increase in publications after 2015. A paper entitled “Pembrolizumab in patients with advanced triple-negative breast cancer: Phase IB KEYNOTE-012 Study” that was published in the Journal of Clinical Oncology by Nanda et al. was the most cited (715 citations). The keywords found in this research were grouped into four clusters: “mechanism,” “vaccination,” “PD-L1,” and “chemotherapy.” The terms “tumor-infiltrating lymphocytes” and “PD-1/PD-L1” are among the latest hotspots, which mostly appeared in 2017. Author keyword analysis revealed that recent trends in breast cancer immunotherapy focus on the triple- negative breast cancer subtype and PD-1/PD-L1 immune checkpoint pathway and inhibitors. This study analyzed global trends in immunotherapy research on breast cancer over the past 10 years and provided insight into the features and research hotspots of the articles in this issue.