Current and future trends of acupuncture as an adjuvant therapy in cancer: A bibliometric and visual analysis

Background: Acupuncture, as one of the representatives of complementary therapies, is often used as an adjunctive therapy in the treatment of cancer and related complications with beneficial results. Methods: We selected the Web of Science Core Collection (WOSCC) database as the data source and searched to obtain relevant literatures on the application of acupuncture in cancer treatment. The relevant literature was analyzed using CiteSpace (version 6.1.R6) and VOSviewer (version 1.6.20). Results: A total of 592 publications were included, with an overall upward trend in the number of publications. There were 135 countries or institutions involved, with China as the most published country. There were 1888 related institutions, and Memorial Sloan Kettering Cancer Center was the institution with the most publications. A total of 3067 authors were involved, and there were obvious collaborations between authors. There were 190 related journals, and J Clin Oncol was the most cited journal. The most frequently occurring keywords were breast cancer and management, but also other related topics such as quality of life, chemotherapy, and complementary. Conclusion: Acupuncture is gaining increasing attention as an adjunctive therapy in cancer treatment programs. Currently, relevant research focuses on acupuncture to alleviate cancer-induced comorbid symptoms, such as pain and insomnia. Future research is gradually shifting toward spiritual care, Colorectal Cancer Surgery, and systematic review.


Introduction
Cancer is the leading cause of death [1] and a study shows that countries with a low Human Development Index are facing a growing cancer burden. [2]There is no doubt that the high incidence of cancer and the low cure rate put a huge strain on the global health system. [3,4]In the data released by the World Health Organization in 2019, cancer is the first or second leading cause of death before the age of 70 in 112 out of 183 countries and the third or fourth leading cause in another 23 countries. [5]In the face of this situation, more and more scholars have begun to pay attention to the mechanism of cancer and the innovation of treatment programs, [5][6][7] and have achieved many research results.Renewal of cancer treatment programs, as well as postoperative adverse effects and complications of cancer, are all topics of concern and urgent problems.
Acupuncture is one of the therapeutic methods of traditional Chinese medicine with an ancient history, characterized by easy operation and high acceptance by patients.10][11] There is a growing body of evidence showing that the use of acupuncture has positive implications for improving cancer-related symptoms and enhancing the quality of life of cancer patients. [12,13]Although this state of affairs is gradually gaining attention among scholars, there has not been a systematic review to organize and summarize the research in this area in detail.Therefore, this study summarizes and combs the research in this field through bibliometric analysis methods to explore the current research hotspots and future research trends.

Search strategy
We searched the Web of Science Core Collection (WOSCC) for literature on acupuncture for cancer.Search terms included "Acupuncture" and synonyms, "Cancer" and synonyms, etc.The publication period was limited to the year 2023.We finally retrieved 2561 articles.Table 1 demonstrates the search strategy.

Inclusion criteria
We included relevant literature published in different academic journals related to acupuncture and cancer.The language of the articles was limited to English and the type of literature was limited to articles and reviews.

Exclusion criteria
We will exclude consultation guides, letters, abstracts, editorials, dissertations, biographies, book reviews, conferences, news, duplicates, publications withdrawn by the authors, etc, which are not relevant to the field of study.

Literature screening process
Two researchers screened the retrieved literature based on the inclusion criteria, and exclusion criteria, and finally 592 publications were included.Figure 1 illustrates the screening process.

Bibliometric analysis software
We used 2 software packages, CiteSpace (version 6.1.R6) and VOSviewer (version 1.6.20)for bibliometric analysis and visualization.We focused on publishing trends, countries/regions, research institutions, authors, keywords cooccurrence and clustering relationships, and forming network analysis views.Table 1 Publication retrieval strategy for acupuncture treatment of cancer.

Rank
Search strategy

Countries/regions analysis
A total of 135 countries/regions are involved in the 592 papers, and Table 2 shows the top 10 countries in terms of the number of papers issued.In Figure 3A, we analyzed the network view of countries/regions, and it can be seen that there is a close cooperation between these countries/regions, which has formed a remarkable cooperation cluster.Among them, China has published the largest number of related publications, reaching 249.USA has the second-largest number of publications, reaching 167.It is followed by South Korea and England with 44 and 43 publications respectively.The network view shows that these 4 countries are at the center of their respective collaborative clusters.Figure 3B illustrates the geographical distribution of these countries, and it can be seen that these countries are distributed in 5 continents around the world, and scholars from each continent have also formed stable collaborations, such as USA-Israel, Canada-Brazil, and China-Indonesia-Iran.China and the United States are also at the core of Asia and the Americas.

Institutions analysis
There are a total of 1888 institutions associated with publications, and Table 3 demonstrates the top 13 institutions in terms of the number of publications, with no <14 publications per institution.The institution with the highest number of publications was the Memorial Sloan Kettering Cancer Center, with a total of 43 publications.The institutions with the second and third largest number of publications were Beijing University of Chinese Medicine and Guangzhou University of Chinese Medicine, with 33 and 24 publications, respectively.When analyzing the institutions by centrality, the China Academy of Chinese Medical Sciences ranked first with 0.21.Korea Institute of Oriental Medicine ranked second with 0.15, followed by Beijing University of Chinese Medicine with 0.12. Figure 4A shows the co-occurrence analysis view of the institutions, with the size of the nodes representing the number of publications.
Figure 4B shows the results of the cluster analysis between institutions, and it can be seen that these institutions can form 10 significant clusters, which suggests that there is a relatively close collaboration between institutions.The cluster with the highest heat level is cancer-related fatigue, followed by postoperative ileus and myeloablative chemotherapy-induced emesis.this reflects the fact that the current research on this topic is mainly focused on cancer-induced complications and adverse reactions caused by surgery, chemotherapy, and other therapeutic modalities.

Authors analysis 3.4.1. Analysis of authors' publications and authors
collaborations.3067 authors contributed to the publications.Table 4 demonstrates the top 8 authors in terms of the number of publications, each of which has published at least 7 papers.Mao, Jun J published 38 papers and is the author with the highest number of publications, closely followed by Bao, Ting with 15 papers.Figure 5A shows the analytical view of the author network constructed based on the number of publications of each author, and the size of the node represents the number of publications.Mao, Jun J, and Zhao, Ling ranked the top 2 scholars in terms of centrality, both with a centrality of 0.02.This indicates that the research results of these 2 scholars have been recognized by researchers in the industry, and they have a high impact.
Figure 5B, on the other hand, illustrates the results of the cluster analysis among authors with high publication volume, which form 10 more significant collaborative clusters, with the larger connecting points in each cluster indicating more  publications by scholars in that cluster.The cluster with the highest heat was Cancer Survivor, followed by Nasopharyngeal Carcinoma and Pilot Randomized.This suggests that acupuncture is mainly used as an alternative and adjunctive therapy for the subsequent rehabilitation of cancer survivors.Acupuncture is primarily involved in the treatment of nasopharyngeal cancer.Scholars have conducted relevant studies mainly through randomized controlled trials.

Analysis of co-cited authors.
Table 5 shows the number of co-citations and centrality of the top 10 authors, and Figure 6A shows the co-occurrence analysis view of the co-cited authors, with the size of the nodes representing the number of citations.It can be found that Anonymous has the highest number of citations with 182 citations and a centrality of 0.07.The scholar with the 2nd highest number of citations is Mao JJ, with 130 citations and a centrality of 0.04, followed by Deng G, with 121 citations and a centrality of 0.09.Among the top 10 authors, the one with the highest centrality is Garcia MK, with 119 citations and 0.09 centrality.This indicates that although Garcia MK does not have the largest number of publications, his research is of highquality and has a greater impact.Figure 6B shows the results of the cluster analysis of these authors, and it can be seen that these authors have formed a more significant cooperative relationship with each other, and the stable cooperative relationship promotes the progress of related research on this topic.

Journals analysis
A total of 190 journals published publications on related topics.Table 6 demonstrates the top 10 most cited journals with centripetal and journal division, impact factor.Figure 7 demonstrates the cited journals, where the top 3 cited journals are J Clin Oncol, Acupunct Med, and Support Care Cancer, with 399, 306, and 287 citations, respectively.Combining the impact factor and partition, the latest impact factor of J CLIN ONCOL is 45.3 points and the partition is Q1, the latest impact factor of Acupunct Med is 2.5 points and the partition is Q3, and the latest impact factor of Support Care Cancer is 3.1 and the partition is Q1. 10 journals include the top journals JAMA-J Am Med Assoc, it can be seen that the research related to acupuncture for cancer treatment has high-quality research results published with authority.The results of cluster analysis showed that the cluster with the highest heat was acupuncture prophylaxis, followed by gastrointestinal tract cancer and myeloablative chemotherapy-induced emesis.This suggests that acupuncture in ameliorating cancer primarily plays a role in preventing gastrointestinal reactions as well as chemotherapy-induced adverse effects.

Analysis of references
[16][17][18][19][20][21][22][23] The network map of co-cited literature presented in Figure 8    of the 10 keywords is acupuncture.The focus of these keywords is centered on female patients and breast cancer, as well as alleviating complications during cancer treatment and improving patients' quality of life through acupuncture.Figure 9 illustrates the co-occurrence analysis view of the keywords, where a larger area of the node indicates a higher number of occurrences.

Keywords clustering analysis.
Figure 10 shows the cluster analysis of the keywords which can be categorized into 15 significant clusters.The most popular cluster is cancer patient care, followed by clinical advice and advanced prostate cancer.

Keywords timeline analysis.
Figure 11 shows the timeline visualization analysis of the keywords, reacting to the evolution of the keywords.It can be seen that scholars initially focused on the topic of cancer patient care, and the hotness of this keyword lasted from 1994 to today.The latest research hotspots focus on spiritual care, Colorectal Cancer Surgery, and systematic review.

Discussion
Based on the search results from the WOSCC, we analyzed the current and future trends in the use of acupuncture as an adjuvant therapeutic measure among cancers.The analysis of countries|/regions shows that China and the United States have published the most literature in this area.There is a cooperative relationship between several countries, forming more significant clusters.China, South Korea, and England are at the center of their respective clusters.
The analysis of institutions showed that Memorial Sloan Kettering Cancer Center was the institution with the highest number of publications, and China Academy of Chinese Medical Sciences ranked 1st in centrality.The cluster analysis of the institutions formed stable clusters, each with a distinct theme, with the hottest theme being cancer-related fatigue.
The results of the authors analysis showed that Mao, Jun J, and Bao, Ting were the 2 authors with the highest number of publications.The 2 scholars with the highest centrality are Mao, Jun J, and Zhao, Ling.The results of the authors' clustering analysis show that the current scholars are mainly focusing on studies related to cancer survivors, nasopharyngeal carcinoma, and pilot randomized.Anonymous is the most cited author and Garcia MK is the most centrally cited author.
The analysis of cited journals shows that J Clin Oncol (Q1/45.3) is the most cited journal.The top 10 cited journals included top journals JAMA-J Am Med Assoc.this suggests that the research on this topic has achieved high-quality results and is authoritative.The results of cluster analysis suggest that acupuncture prophylaxis, gastrointestinal tract cancer, and myeloablative chemotherapy-induced emesis are the research topics of greater interest to scholars.
Analysis of the references revealed 592 documents with 911 co-references and the highest number of citations at 51, published in JAMA Oncol.This publication focuses on the results of a systematic evaluation and meta-analysis of acupuncture combined with acupressure for the amelioration of pain associated with cancer, which provides evidence-based support for research on this topic.
The results of the keyword analysis demonstrated the research directions that scholars focus on in this field.breast cancer is the keyword with the highest frequency of occurrence.Among the top 10 keywords with the highest frequency of occurrence, we found both quality of life, Pain, and therapy.these keywords demonstrated the current major focus of acupuncture to improve cancer.Cluster analysis revealed that the keywords could be clustered into 15 clusters, with cancer patient care being the most popular cluster.Timeline analysis showed spiritual care, Colorectal Cancer Surgery, and systematic review as the most recent themes.

Limitation
Although we tried to maintain the rigor of this study as much as possible, certain limitations remain.We only included articles from the WOS core library and therefore did not guarantee the inclusion of all studies on this topic.Due to the extensive nature of the search measurement strategy, we manually screened the retrieved literature.Therefore, the literature   [15] included in this study is accurate but may not be comprehensive.

Conclusion
This study found that research under this theme has focused on the application of acupuncture therapy to improve the quality of life of cancer patients, with positive findings in the improvement of cancer-induced pain and insomnia.In addition.We found that spiritual care for cancer patients, postoperative adverse effects of colorectal cancer, and systematic review became new research hotspots, which suggests future research trends.In conclusion, acupuncture has a positive role and prospects as a complementary and alternative therapy in improving cancer-related symptoms.Table 8 The keywords with the frequency of occurrence.

Figure 2
Figure 2 shows the number of publications between 1985 and 2023, with an overall upward trend.The number of publications between 1985 and 2007 is relatively low, with an average of no more than 10 publications per year.The number of publications between 2008 and 2013 shows an increasing trend and reached 30 in 2013.The number of publications between 2013 and 2020 is no <20 per year and exceeds 60 in 2020.After 2020, the number of publications shows a clear upward trend, reaching a peak of over 80 in 2023.

Figure 3 .
Figure 3. Visual analysis of countries/regions.(A) Network view analysis.(B) Countries distribution map.

Figure 4 .
Figure 4. Network analysis view of publishing institutions.(A) Co-occurrence analysis view of institutions.(B) Cluster analysis view of institutions.

Figure 6 .
Figure 6.Network analysis view of cited authors.(A) Co-occurrence analysis view.(B) Clustering analysis view.

Figure 5 .
Figure 5. Author network analysis view.(A) Author co-occurrence analysis.(B) Author cluster analysis.

Figure 8 .
Figure 8.View of co-occurrence analysis of references.

Table 2
Top 10 countries/region in terms of publication volume.

Table 3
Top 13Institutions with the highest number of publications.

Table 4
Top 8 authors in terms of publication volume.

Table 5
Top 10 scholars with citation times.

Table 6
Top 10 journals ranked in citation times.