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Hum Vaccin Immunother
Hum Vaccin Immunother
Human Vaccines & Immunotherapeutics
2164-5515
2164-554X
Taylor & Francis

10.1080/21645515.2024.2393485
2393485
Version of Record
Letter to the Editor
Immunotherapy - Cancer
Comment on “Bibliometric analysis reveals the research hotspots and trends of nasopharyngeal carcinoma immunotherapy”
H. BAI ET AL.
HUMAN VACCINES & IMMUNOTHERAPEUTICS
Bai Heng a
Liu Si-Yang a
Tian Jie b
Li Yu a
a Department of General Practice/Department of Geriatrics, The Affiliated Hospital of Northwest University , Xi’an, Shaanxi, China
b Department of Thoracic Surgery/Lung Cancer Center, West China Hospital, Sichuan University , Chengdu, Sichuan Province, China
CONTACT Jie Tian tianjiehxxwk@163.com Department of Thoracic Surgery/Lung Cancer Center, West China Hospital, Sichuan University, No. 37, Guoxue Lane, Wuhou District, Chengdu, Sichuan Province 610041, China.
Yu Li liyu1127@126.com Department of General Practice/Department of Geriatrics, Xi’an No.3 Hospital, The Affiliated Hospital of Northwest University, Xi’an, Shaanxi 710018, China.
30 8 2024
2024
30 8 2024
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© 2024 The Author(s). Published with license by Taylor & Francis Group, LLC.
2024
The Author(s)
https://creativecommons.org/licenses/by-nc/4.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (http://creativecommons.org/licenses/by-nc/4.0/), which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited. The terms on which this article has been published allow the posting of the Accepted Manuscript in a repository by the author(s) or with their consent.

The author (s) reported there is no funding associated with the work featured in this article.
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pmc Dear Editor,

We have recently taken an interest in the article by Wang et al. titled “Bibliometric analysis reveals the research hotspots and trends of nasopharyngeal carcinoma immunotherapy”.1 This study delves into the immunotherapy for nasopharyngeal carcinoma (NPC), providing detailed insights and attempting to forecast future research directions through bibliometric analysis. While the findings are indeed valuable, we propose enhancing the information retrieval methods to improve the comprehensiveness and reliability of future research. Furthermore, incorporating the H-index, an essential metric for evaluating the academic productivity and impact of researchers,2 is recommended. Additionally, examining institutional collaborations could shed light on both domestic and international partnerships.

Effective search strategies are essential in bibliometric analyses. Wang et al.’s study sourced its original data from the Web of Science Core Collection (WoSCC), which includes sub-databases such as the Science Citation Index Expanded (SCI-EXPANDED) and the Social Sciences Citation Index (SSCI). Prior research indicates that combining multiple sub-databases may not always produce the best results.3,4 Therefore, it is generally recommended to avoid merging several databases into one analysis due to the potential for increased complexity. Notably, SCI-EXPANDED is often regarded as the most reliable source for such studies.3–5 It is important for researchers to specify the databases they use to ensure both the reproducibility and relevance of the study, thereby enhancing the quality of the bibliometric evaluation.3,4

A key element of bibliometric research is the development of precise search terms and strategies. Wang et al. utilized a Topic Search (TS) that included terms from the “Title (TI),” “Abstract (AB),” “Author Keywords (AK),” and “Keywords Plus (KP).” However, “KP” terms are generated by the WoSCC’s algorithms and may include irrelevant publications. Our research suggests that focusing solely on “TI,” “AB,” and “AK” improves the precision and relevance of the data collected.4 In our analysis, we refined these search terms, resulting in more accurate data collection. Details of the revised search strategy are provided in Supplementary Table S1.

Furthermore, the H-index is a crucial metric for evaluating the quantity and quality of a researcher’s academic contributions. Defined as the number of a scholar’s publications (H) that have been cited at least H times, this index highlights the impact of their most significant works.2 It serves as a robust indicator of academic influence, focusing on research that receives substantial recognition and citations. We calculated the H-index for researchers using the Web of Science online platform (https://webofscience.clarivate.cn/).

With our refined search methodology, we curated a dataset of 423 papers published before January 17, 2024. The search was conducted on August 3, 2024. After removing irrelevant records, we analyzed 399 papers. Figure 1a presents the annual distribution of these publications. Our analysis reveals a significant rise in research on “the application and trend of nasopharyngeal carcinoma immunotherapy” beginning in 2016, indicating a growing interest in this area. The fifth-degree polynomial model forecasts that this upward trend will persist, aligning with the increasing research attention in the field. According to the fitting curve, the number of publications in 2024 is projected to reach approximately 85, marking an increase of about 22.5%. Figures 1b-f illustrate the geographical distribution of corresponding authors and the networks of international collaboration among different countries, institutions, and journals. China emerges as the leading contributor, followed by the United States and Australia (Figure 1c). Figure 1. A bibliometric analysis of nasopharyngeal carcinoma immunotherapy. (a) The annual publication trends over the last two decades are depicted, with a red trend curve fitted to the number of publications using a fifth-order polynomial model. (b) A geospatial map displays the countries of corresponding authors. (c-d) VOSviewer visualizations show the networks of international collaborations among various countries and institutions. (e) The top 10 authors in nasopharyngeal carcinoma immunotherapy research are highlighted. (f-g) visualizations illustrate the networks of international collaborations among different journals and manuscript citations. Node size and color denote quantity and category, respectively, while connecting lines represent collaboration or co-citation levels. (h) A word cloud emphasizes the frequency of author keywords, with larger font sizes indicating higher occurrence. (i) The top 20 references with the strongest citation bursts are listed. (j) The top 20 keywords with the strongest citation bursts are identified.

Figure 1d highlights the institutional collaborations, showing both national and international partnerships. The top three institutions are the Sun Yat Sen University, Chinese University of Hong Kong, and Central South University. Qiu-Yan Chen stands out as the most prolific author with an H-index of 10, indicating substantial contributions (Figure 1e). Despite Rajiv Khanna and Riccardo Dolcetti having published only 8 and 7 articles respectively, their H-index of 8 and 7 signifies that their work is highly impactful and frequently cited (Figure 1e). “Frontiers in Immunology” is recognized as the leading journal with the highest number of published articles (Figure 1f). Our bibliographic coupling analysis points to the work of Ma et al. as the most cited (5) (Figure 1g). This study primarily showcased the antitumor activity of Nivolumab in recurrent and metastatic NPC. The most frequently appearing keywords are depicted in a word cloud in Figure 1h, with “Immunotherapy” being the most prominent term. Figure 1i highlights the top 20 references with significant citation bursts, offering insights into key literature in this field. Figure 1j showcases the top 20 keywords with significant citation bursts, suggesting future trends in NPC immunotherapy, particularly emphasizing the antitumor activity of pembrolizumab.

In comparison to the findings by Wang et al., our study encompasses a smaller corpus of literature on NPC immunotherapy, analyzing a total of 399 papers in contrast to their 513. This reduction not only suggests that the inclusion of some irrelevant literature by Wang et al. may have skewed the results, but it also enhances the robustness of our findings. Furthermore, it provides a more comprehensive and accurate representation of various bibliometric indicators, such as publication and citation metrics, and the impact of contributing countries, institutions, authors, journals, keywords, and references. This change underscores the importance of a meticulously crafted search strategy to ensure an unbiased bibliometric analysis. Integrating expert feedback to refine search terms tailored to specific research areas is key to improving precision. Our research provides more focused guidance and serves as a valuable reference for scholars in the field of NPC immunotherapy. Additionally, by incorporating the H-index as an analytical tool, we emphasize the academic impact of researchers, thereby enhancing the overall value of the study.

In summary, while we acknowledge the foundational contributions of Wang et al.1, our methodological improvements effectively address prior limitations and pave the way for more comprehensive and insightful bibliometric research. We encourage future researchers to adopt and refine these advanced strategies to improve the quality and impact of their work across diverse scientific disciplines.

Supplementary Material

Supplementary Table 1.docx

Heng Bai a general practitioner at Xi’an No.3 Hospital, The Affiliated Hospital of Northwest University. Primarily engaged in general practice-related work.

Si-Yang Liu a general practitioner at Xi’an No.3 Hospital, The Affiliated Hospital of Northwest University. Primarily engaged in general practice-related work.

Jie Tian Resident Physician, Doctoral Candidate at West China Hospital, Sichuan University. Primarily engaged in surgical-related work.

Yu Li Department Director/Chief Physician/Doctor of Medicine.

B iographical Notes

Academic Positions: Currently serves as a national committee member of the Fourth Hypertension Professional Committee of the Chinese Medical Doctor Association, a standing committee member of the Hypertension Professional Committee of the Shaanxi Health Medical Association, a member of the Xi’an Medical Technology Identification Expert Database, a standing committee member of the Chest Pain Professional Committee of the Shaanxi Medical Promotion Association, and a standing committee member of the Xi’an Geriatrics Society.

Professional Expertise: With over 20 years of experience in clinical practice, teaching, and research in cardiology, Yu Li has undergone extensive clinical training at the Department of Cardiology, First Affiliated Hospital of Xi’an Jiaotong University School of Medicine during her master’s and doctoral studies. In 2009, Yu Li furthered her training at the Heart Center of Bergmannsheil Hospital, Ruhr University in Germany. With more than two decades of clinical practice, Yu Li has accumulated rich experience, particularly in diagnosing and treating complex and critical cardiovascular diseases, earning the trust of his patients. Yu Li specializes in the diagnosis and treatment of hypertension and its complications, refractory hypertension, secondary hypertension, gestational hypertension, metabolic syndrome, sleep apnea syndrome, coronary heart disease, heart failure, and arrhythmias.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Authors’ contribution

Heng Bai, Si-Yang Liu, Jie Tian and Yu Li organized and designed the manuscript. Heng Bai, Si-Yang Liu, Jie Tian and Yu Li organized and edited the retrieval formula. Heng Bai, Si-Yang Liu, Jie Tian and Yu Li created the Figure and Tables. All authors wrote the manuscripts and reviewed the finally version.

Data availability statement

The datasets used during the present study are available from the corresponding authors upon reasonable request.

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website at https://doi.org/10.1080/21645515.2024.2393485
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References

1. Wang G, Zou XS, Weng JJ, Lan GP, Li M, Wei JZ, Nong W, Chen Q, Miao W, Luo H, et al. Bibliometric analysis reveals the research hotspots and trends of nasopharyngeal carcinoma immunotherapy. Hum Vaccin Immunother. 2024 Jul 21;20 (1 ). doi: 10.1080/21645515.2024.2360341.
2. Tam J, Lagisz M, Cornwell W, Nakagawa S. Quantifying research interests in 7,521 mammalian species with h-index: a case study. Gigascience. 2022 Aug 13;11 :giac074. doi: 10.1093/gigascience/giac074.35962776
3. Wu HY, Cheng KM, Li C. Ferroptosis, necroptosis, pyroptosis, and cuproptosis in cancer: a comparative bibliometric analysis. Cell Death Discov. 2023 Jul 10;9 (1 ):238. doi: 10.1038/s41420-023-01542-7.37429861
4. Cheng KM, He YB, Gu SQ, Wu HY, Li C. A commentary on ‘evolutionary patterns and research frontiers in neoadjuvant immunotherapy: a bibliometric analysis’. Int J Surg. 2023 Sep 1. 109 (9 ):2829–3. doi: 10.1097/JS9.0000000000000529.37352515
5. Ma BBY, Lim WT, Goh BC, Hui EP, Lo KW, Pettinger A, Foster NR, Riess JW, Agulnik M, Chang AYC, et al. Antitumor activity of Nivolumab in recurrent and metastatic nasopharyngeal carcinoma: an international, multicenter study of the mayo clinic phase 2 consortium (NCI-9742). J Clin Oncol. 2018 May 10;36 (14 ):1412–1418. doi: 10.1200/JCO.2017.77.0388.29584545
