Acupuncture and Related Therapies for Breast Cancer-Related Symptoms: An Evidence Map

Abstract

Background

Breast cancer is the most frequent malignancy among women worldwide. Despite advances in medical treatment, many survivors experience distressing symptoms and therapy-related side effects that impair quality of life. Acupuncture-related therapies are increasingly employed as supportive care strategies, yet their evidence base remains fragmented.

Objective

To construct an evidence map of systematic reviews (SRs) and meta-analyses evaluating acupuncture and related therapies for breast cancer-related symptoms.

Methods

Searches were performed in PubMed, Embase, and Cochrane Database of Systematic Reviews, China National Knowledge Infrastructure (CNKI), Wanfang, Research Information Service System (RISS), Oriental Medicine Advanced Search Integrated System (OASIS), and Korean Studies Information Services System (KISS) from inception to April 24, 2025. Eligible SRs included breast cancer populations, any acupuncture-related intervention, and reported outcomes relevant to symptom management or treatment side effects. Data extraction included bibliographic details, intervention type, outcomes, number of studies, sample size, effect direction, and methodological quality (AMSTAR-2). Evidence was synthesized descriptively and presented using heatmaps.

Results

A total of 47 SRs with meta-analysis were included, covering 11 distinct symptom domains and 6 categories of interventions. The most frequently studied outcomes were hot flashes (n=9), general supportive care during chemotherapy (n=9), lymphedema (n=7), general side effect management (n=6), and aromatase inhibitor-associated arthralgia (n=4). The most common interventions were acupuncture (n=17), acupuncture combination therapies (n=16), and acupoint injection (n=9). Across the included SRs, 20 reported positive effects, 23 were mixed, and 4 reported no clear evidence of benefit. Only 8 of 47 SRs achieved moderate confidence, and none were rated high, indicating widespread methodological limitations across the evidence base (29 low, 10 critically low).

Conclusion

Acupuncture and related therapies are widely studied as supportive care strategies for breast cancer-related symptoms with promising evidence. However, the majority of SRs are of low methodological quality. High-quality trials and rigorously conducted systematic reviews are needed to strengthen the evidence base, reduce redundancy, and guide integrative oncology practice.

Introduction

Breast cancer is the most common malignancy among women and a leading cause of cancer-related morbidity worldwide. ¹ Advances in surgery, chemotherapy, radiotherapy, endocrine therapy, and targeted agents have significantly improved survival rates. ² Yet, patients frequently experience distressing symptoms and side effects such as postoperative pain, hot flashes, nausea, fatigue, and sleep disturbance.^3-5 These conditions negatively affect quality of life, interfere with daily functioning, and may even reduce adherence to treatment regimens, ultimately compromising clinical outcomes. ⁶ Over the past two decades, interest has grown in acupuncture and related therapies as supportive care options for breast cancer patients.^7,8 Modalities such as manual and electroacupuncture, auricular acupressure, acupressure, moxibustion, and acupoint injection have been evaluated in randomized controlled trials and systematic reviews. ⁹ Evidence suggests benefits of acupuncture and related therapies for specific outcomes such as pain, insomnia, and fatigue,^10-13 but these findings remain inconclusive due to heterogeneity, small sample sizes, and variable methodological quality. ¹⁴ Clinical guidelines such as those from the National Comprehensive Cancer Network (NCCN)^15,16 and the Society for Integrative Oncology (SIO)^17,18 cautiously endorse acupuncture-related therapies for selected indications (e.g., pain, hot flashes, nausea), while highlighting the need for more rigorous evidence. While several SRs exist, substantial overlap among primary studies and inconsistent findings across reviews due to variable methodological quality necessitate a comprehensive overview. An evidence map serves this purpose by systematically synthesizing the scope, direction, and quality of existing SRs. ¹⁹ Unlike meta-analysis, which addresses a specific question, evidence maps provide a broader overview, highlighting areas of evidence concentration, uncertainty, and gaps. The aim of this study was to develop an evidence map of systematic reviews on acupuncture and related therapies for treatment-related symptoms in breast cancer populations.

Methods

Eligibility Criteria

We defined eligibility criteria based on Population, Intervention, Comparator, Outcomes, Study design (PICO) framework. The protocol of this evidence-mapping study was prospectively registered in PROSPERO (CRD420251167030). This study was conducted with consideration of methodological guidance for overviews of reviews, including the Preferred Reporting Items for Overviews of Reviews (PRIOR) statement, ²⁰ and the search strategy was reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses literature search extension (PRISMA-S) recommendations. ²¹ The completed PRIOR and PRISMA-S reporting checklists are provided in Supplementary 3 and 4, respectively.

Population: Systematic reviews (SRs) focusing on breast cancer, irrespective of stage or survivorship status were included.

Interventions: SRs evaluated acupuncture and related therapies, including manual acupuncture, electroacupuncture, auricular acupuncture, acupressure, auricular acupressure, moxibustion, and acupoint injection, were eligible. In this study, acupuncture and related therapies were used as an umbrella term encompassing acupuncture-based and acupoint-based interventions.

Comparators: All comparators were eligible, including sham controls, usual care, waitlist, active drug treatment, or no intervention.

Outcomes: SRs focused on breast cancer–related symptoms and treatment side effects, such as postoperative pain, chemotherapy-induced nausea and vomiting, and cancer-related fatigue, among others, were eligible.

Study design: Only SRs with meta-analysis were included. Narrative reviews, scoping reviews, or other types of reviews were excluded.

Search Strategy

A comprehensive literature search was conducted from database inception to April 24, 2025 in the following electronic databases: PubMed, Embase, and Cochrane Database of Systematic Reviews for English-language SRs and China National Knowledge Infrastructure (CNKI) and Wanfang for Chinese-language SRs and Research Information Service System (RISS), Oriental Medicine Advanced Search Integrated System (OASIS), and Korean Studies Information Services System (KISS) for Korean-language SRs. The search combined controlled vocabulary and free-text terms for breast cancer, acupuncture and related therapies, and systematic reviews. No restrictions were applied for language or publication date. The detailed search strategy for each database is provided in Supplementary 1.

Study Selection and Data Extraction

All search results were imported into EndNote for de-duplication and screening. Two reviewers (T-Y C and JHJ) independently screened titles and abstracts, followed by full-text articles against the eligibility criteria. Any discrepancies were resolved by discussion or, when necessary, by consultation with a third reviewer (LA). Data were independently extracted using a standardized template, including first author, country of the first author, breast cancer-related symptoms, type of acupuncture-related intervention, number of included trials, total sample size, effect direction, and overall methodological confidence rating according to AMSTAR-2. ²²

Effect direction was classified as a descriptive indicator to summarize findings across systematic reviews. Reviews were categorized as positive when the majority of reported comparisons favored the intervention with statistical significance, mixed when findings were inconsistent, and no clear evidence when results were predominantly non-significant. This classification was intended for descriptive mapping purposes only and does not represent a formal synthesis of effect size or strength of evidence. Intervention terminology and symptom domains were recorded as reported in the included SRs. When specific acupuncture modalities (e.g., manual acupuncture or electroacupuncture) were described, these were listed accordingly; otherwise, original terminology (e.g., acupuncture) was retained. SRs pooling two or more acupuncture-related modalities without reporting modality-specific effects were categorized as acupuncture combination. Acupoint injection was classified as an acupuncture-related therapy based on its acupoint-based application, but was analyzed as a separate intervention category due to its pharmacological nature and differing regulatory considerations. Outcomes were extracted as reported in the included systematic reviews and were not reclassified based on measurement type; therefore, both validated patient-reported outcomes and composite or surrogate outcomes may be represented.

Quality Appraisal

Methodological quality of included systematic reviews was independently assessed by two reviewers using the AMSTAR-2 tool. ²² AMSTAR-2 consists of 16 domains evaluating key aspects of review methodology, including protocol registration, comprehensiveness of the search strategy, risk of bias assessment, and appropriateness of meta-analytic methods. Based on AMSTAR-2 guidance, overall confidence ratings (high, moderate, low, or critically low) were determined according to the presence of critical and non-critical weaknesses. Reviews with no or one non-critical weakness were rated as high confidence, those with more than one non-critical weakness as moderate, those with one critical flaw as low, and those with more than one critical flaw as critically low. Any disagreements were resolved through discussion. The detailed AMSTAR-2 appraisal for each included systematic review is provided in Supplementary 2.

Data Synthesis and Evidence Mapping

A descriptive synthesis of included reviews, summarizing the distribution of interventions, outcomes, number of reviews, number of primary studies, and methodological quality were performed. To visualize the evidence, a heatmap was constructed, with symptom domains on the y-axis and intervention types on the x-axis. Each cell displayed the direction of effect, number of reviews, and AMSTAR-2 confidence level. SRs addressing broader categories such as general supportive care or general side effect management were also included in the heatmap but coded separately. SRs addressing multiple outcomes or intervention types were mapped to all relevant cells to reflect evidence coverage, without double-counting reviews within individual cells.

Results

Study Selection

The database search identified 1054 records. After removing 244 duplicates, 810 titles and abstracts were screened, of which 705 were excluded for not meeting eligibility criteria. Of the 105 reports sought for retrieval, 29 could not be retrieved; the remaining 76 full-text articles were assessed for eligibility, of which 29 were excluded. The main reasons for exclusion were mixed TCM treatment (n=15), absence of meta-analysis (n=11), duplicates (n=2), or not acupuncture-related interventions (n=1). Ultimately, 47 SRs with meta-analysis were included in the final evidence map. A PRISMA 2020 flow diagram summarizing the study selection process is provided in Figure 1.

Figure 1.

PRISMA diagram for the included studies. AT: acupuncture, BC: breast cancer, MA: meta-analysis, SR: systematic reviews, TCM: traditional Chinese medicine

Characteristics of Included Reviews

A total of 47 SRs with meta-analysis were included in the evidence map. These reviews investigated 11 distinct breast cancer–related symptoms or treatment side effects and assessed 6 categories of acupuncture-related interventions.

The most frequently studied outcomes were general supportive care during chemotherapy (n=9) and hot flashes (n=9), followed by lymphedema (n=7), general side effect management (n=6), and aromatase inhibitor–associated arthralgia (n=4). Other outcomes addressed included insomnia (n=3), aromatase inhibitor–associated musculoskeletal symptoms (n=2), cancer-related fatigue (n=2), postoperative pain (n=2), chemotherapy-induced nausea and vomiting (n=2), and leukopenia (n=1). Psychological outcomes such as anxiety and depression were not identified among the included systematic reviews meeting the eligibility criteria.

Interventions most commonly assessed were acupuncture alone (n=17) and acupuncture combination therapies (n=16). Other modalities included acupoint injection (n=9), acupressure (n=2), auricular acupressure (n=2), and moxibustion (n=1). Reporting of adverse events was limited and inconsistent across the included systematic reviews, and therefore safety outcomes could not be comprehensively summarized. Details of the included SRs were presented in Table 1.

Table 1.

Basic Characteristics of Included Systematic Reviews With Meta-Analysis

First authors	Country	Breast cancer-related symptoms	Intervention	Included trials (n)	Sample size (n)	Effect direction	Overall confidence
Zhang 2025 23	China	Hot flashes	Acupuncture	11	963	Mixed	Moderate
Salehi 2016 24	Iran	Hot flashes	Acupuncture	12	680	No clear evidence	Critically Low
Lee 2009 25	Korea	Hot flashes	Acupuncture combination (manual acupuncture and electroacupuncture)	6	189	No clear evidence	Low
Li 2021 26	China	Hot flashes	Acupuncture combination (manual acupuncture, electroacupuncture, acupressure, auricular acupuncture, and moxibustion)	26	2055	Positive	Critically Low
Chien 2017 27	Taiwan	Hot flashes	Acupuncture	13	844	Positive	Low
Lu 2018 28	China	Hot flashes	Acupuncture	9	585	Mixed	Low
Chen 2016 29	China	Hot flashes	Acupuncture combination (manual acupuncture, electroacupuncture, auricular acupuncture, and acupoint injection)	12	672	Mixed	Low
Chiu 2016 30	Taiwan	Hot flashes	Acupuncture combination (manual acupuncture, electroacupuncture, and scalp acupuncture)	7	342	Mixed	Low
Wang 2018 31	China	Hot flashes	Acupuncture combination (manual acupuncture and electroacupuncture)	18	555	Mixed	Low
Zhang 2019 32	China	Lymphedema	Acupuncture	6	318	Positive	Critically Low
Gao 2021 33	China	Lymphedema	Acupuncture combination (acupuncture and moxibustion)	14	758	Positive	Low
Jin 2020 34	China	Lymphedema	Acupuncture combination (acupuncture and moxibustion)	12	778	Positive	Low
Hou 2019 35	China	Lymphedema	Acupuncture	13	747	Mixed	Low
Yu 2020 36	China	Lymphedema	Acupuncture combination (acupuncture, electroacupuncture, warm acupuncture, and cupping)	8	519	Mixed	Low
Chien 2019 37	Taiwan	Lymphedema	Acupuncture	6	178	Mixed	Low
Yang 2024 38	China	Lymphedema	Acupuncture	14	952	Positive	Critically Low
Qi 2022 39	China	Aromatase inhibitor-associated arthralgia	Acupuncture	9	592	Positive	Critically Low
Huang 2022 40	China	Aromatase inhibitor-associated arthralgia	Acupuncture	8	652	Mixed	Critically Low
Liu 2021 41	China	Aromatase inhibitor- associated arthralgia	Acupuncture combination (manual acupuncture, auricular acupuncture, and electroacupuncture)	7	603	Positive	Low
Chen 2017 42	Taiwan	Aromatase inhibitor-associated arthralgia	Acupuncture	5	181	Mixed	Low
Chien 2015 43	Taiwan	Aromatase inhibitor–associated musculoskeletal symptoms	Acupuncture combination (manual acupuncture, electroacupuncture, and auricular acupuncture)	5	207	No clear evidence	Low
Lu 2022 44	China	Aromatase inhibitor-associated musculoskeletal symptoms	Acupuncture combination (manual acupuncture, electroacupuncture, and auricular acupuncture)	5	462	Positive	Low
Xin 2024 45	China	Insomnia	Auricular acupressure	11	1199	Positive	Moderate
Huang 2025 46	China	Insomnia	Auricular acupressure	15	1125	Mixed	Low
Weng 2024 47	China	Insomnia	Acupuncture combination (manual acupuncture, electroacupuncture, auricular acupuncture, and auricular acupressure)	7	434	Mixed	Moderate
Bae 2024 48	Korea	Cancer-related fatigue	Moxibustion	10	744	Positive	Moderate
Choi 2022 49	Korea	Cancer-related fatigue	Acupuncture combination (manual acupuncture and electroacupuncture)	14	1223	Mixed	Moderate
Yan 2018 50	China	Chemotherapy-induced nausea and vomiting	Acupressure	6	276	Positive	Low
Issac 2024 51	India	Chemotherapy-induced nausea and vomiting	Acupressure	6	287	Positive	Low
Ma 2023 52	China	Postoperative pain	Acupuncture	10	944	Positive	Low
Zhang 2023 53	China	Postoperative pain	Acupuncture	13	1109	Positive	Critically Low
Shih 2021 54	Taiwan	Leukopenia	Acupuncture combination (manual acupuncture, electroacupuncture, catgut embedding, and moxibustion)	10	650	Positive	Moderate
Jang 2020 55	Korea	General side effect management	Acupuncture combination (manual acupuncture and electroacupuncture)	19	1216	No clear evidence	Low
Chan 2021 56	Hong Kong	General side effect management	Acupuncture	16	1230	Positive	Critically Low
Chien 2020 57	Taiwan	General side effect management	Acupuncture	13	943	Mixed	Critically Low
Zhang 2021 58	China	General side effect management	Acupuncture combination (manual acupuncture and electroacupuncture)	29	2094	Mixed	Low
Pan 2020 59	China	General side effect management	Acupuncture	20	1261	Mixed	Low
Pan 2018 60	China	General side effect management	Acupuncture	17	585	Mixed	Low
Wu 2019 61	China	General supportive care during chemotherapy	Acupoint injection (Shenqi Fuzheng injection)	20	2095	Positive	Low
Wu 2021 62	China	General supportive care during chemotherapy	Acupoint injection (Aidi injection)	18	1449	Positive	Low
Liu 2019 63	China	General supportive care during chemotherapy	Acupoint injection (Shenqi Fuzheng injection)	31	2543	Positive	Moderate
Yang 2018 64	China	General supportive care during chemotherapy	Acupoint injection (Shenqi Fuzheng injection)	7	543	Mixed	Critically Low
Xue 2018 65	China	General supportive care during chemotherapy	Acupoint injection (Kangai injection)	15	1201	Mixed	Low
Zhang 2019 66	China	General supportive care during chemotherapy	Acupoint injection (Shenqi Fuzheng injection)	16	1358	Mixed	Low
Chai 2020 67	China	General supportive care during chemotherapy	Acupoint injection (Aidi injection)	18	1452	Mixed	Low
Lv 2015 68	China	General supportive care during chemotherapy	Acupoint injection (Shenqi Fuzheng injection)	18	1247	Mixed	Low
Ao 2019 69	China	General supportive care during chemotherapy	Acupoint injection (Compound Kushen injection)	16	1315	Mixed	Moderate

Note. Intervention terminology was extracted as reported in the included systematic reviews. When specific acupuncture modalities were explicitly described (e.g., manual acupuncture, electroacupuncture), these were listed accordingly. When reviews did not specify modality details, the original terminology (e.g., acupuncture) was retained. The term acupuncture combination refers to systematic reviews that pooled two or more acupuncture-related modalities across included trials without reporting modality-specific effects; it does not necessarily indicate that combined interventions were delivered concurrently within individual trials.

Regarding effect direction, most SRs reported mixed findings (n=23), while 20 SRs suggested positive effects and 4 reviews reported no clear evidence of benefit. Methodological quality, as assessed by AMSTAR-2, was generally limited, with 29 SRs rated as low confidence, 10 as critically low, and only 8 as moderate. No SR achieved a high rating (Supplementary 2).

Evidence by Symptom Domain

Hot Flashes

Nine SRs^23-31 evaluated acupuncture-related therapies for hot flashes in breast cancer patients. Most assessed manual acupuncture or acupuncture combination therapies. The majority of SRs suggested potential benefits, though results were not entirely consistent. Several meta-analyses demonstrated significant reductions in hot flash frequency and severity, while others reported mixed findings. Overall confidence, as judged by AMSTAR-2, was predominantly low to moderate.

Lymphedema

Seven SRs^32-38 focused on acupuncture-related therapies for lymphedema management following breast cancer treatment. Interventions included acupuncture and acupuncture combination. Evidence suggested some potential benefit in reducing arm circumference and improving symptoms; however, results were inconsistent across studies. Most SRs were rated as low confidence, limiting the strength of conclusions.

Aromatase Inhibitor–Associated Arthralgia

Four SRs^39-42 specifically investigated acupuncture for aromatase inhibitor–associated arthralgia. Most found that acupuncture reduced joint pain. The overall effect direction leaned positive, though the strength of evidence was constrained by low to critically low methodological quality of SRs.

General Supportive Care During Chemotherapy

Nine SRs^61-69 examined acupoint injections for general supportive care in patients undergoing chemotherapy. These SRs often included multiple outcomes, such as overall effective rate, immune function, and quality of life measures, without always reporting symptom-specific results. The evidence was largely mixed, reflecting variability across interventions and outcomes. Most SRs were rated low or critically low in methodological quality.

General Side Effect Management

Six SRs^55-60 addressed general side effect management as a broad outcome category. These SRs included multiple outcomes such as pain, fatigue, nausea, and gastrointestinal symptoms. Findings were mixed, with some reporting positive effects of acupuncture-related interventions, while others were inconclusive. Confidence levels were predominantly low.

Other Symptoms

Several additional symptoms were assessed in fewer SRs. These included aromatase inhibitor–associated musculoskeletal symptoms where a small number of SRs^43,44 suggested possible benefit, though findings remain preliminary. For cancer-related fatigue, SRs of acupuncture combination therapies ⁴⁹ and moxibustion ⁴⁸ yielded mixed results, with some evidence of benefit for moxibustion. Three SRs^45-47 evaluated auricular acupressure and acupuncture for insomnia, with one review reporting positive effects and the other two mixed or modest effects. Two SRs^52,53 addressed postoperative pain with positive findings. For chemotherapy-induced nausea and vomiting, 2 SRs^50,51 of acupressure suggested positive benefits. Limited evidence was available for leukopenia, ⁵⁴ though the available evidence suggested benefit.

Evidence Map

Across symptom domains, the evidence map demonstrates that acupuncture and related therapies are most frequently studied for hot flashes, supportive care during chemotherapy, lymphedema, and treatment-related side effects, with smaller numbers of SRs addressing fatigue, sleep disturbance, and arthralgia. While positive findings were reported in 20 SRs, nearly half of the included SRs were judged to have mixed results (n = 23), and methodological quality was predominantly low or critically low (39 of 47 SRs). This evidence map highlights areas requiring more rigorous, high-quality research (Figure 2).

Figure 2.

Evidence map of acupuncture and related therapies in breast cancer symptom management. Rows represent symptom domains, and columns represent acupuncture-related therapies. Cell colors denote effect direction (green = positive, yellow = mixed, red = no clear evidence of benefit). Shading intensity indicates the number of systematic reviews (darker shading = more SRs). Within-cell notation indicates AMSTAR-2 confidence levels (e.g., “C:2/L:3/M:1”), where C = critically low, L = low, and M = moderate

Discussion

Summary of Evidence

This evidence map is the first to systematically chart the landscape, effect direction, and methodological quality of SRs concerning acupuncture and related therapies in breast cancer supportive care. Our findings reveal a rapidly expanding evidence base across various symptom domains (47 SRs with meta-analysis), with the highest concentration of research targeting hot flashes, general supportive care during chemotherapy, lymphedema, general side effect management, and aromatase inhibitor–associated arthralgia. Less commonly investigated outcomes included cancer-related fatigue, insomnia, postoperative pain, and leukopenia. Overall, 20 SRs reported positive effects, particularly for lymphedema, musculoskeletal pain, and general supportive care, while 23 SRs yielded mixed findings and 4 reported no clear evidence of benefit. Our findings are generally consistent with current integrative oncology clinical practice guidelines, which cautiously recommend acupuncture for selected symptoms such as pain, hot flashes, and aromatase inhibitor-associated musculoskeletal symptoms while emphasizing the need for higher-quality evidence.^15-18 The classification of effect direction was based on reported statistical significance within systematic reviews and may be influenced by vote-counting approaches, which have recognized methodological limitations. Therefore, these findings should be interpreted cautiously and not as a substitute for formal quantitative synthesis.

The Critical Issue of Methodological Quality

The synthesis highlights a profound disparity between the volume of evidence and its quality. We identified 47 SRs with meta-analysis, yet only 8 achieved ‘Moderate’ confidence, and none were rated as ‘High’ according to AMSTAR-2 criteria. The vast majority of SRs (83%) were assessed as having ‘Low’ or ‘Critically Low’ methodological quality. This pervasive methodological limitation seriously compromises the certainty of the findings and indicates that many published conclusions may be unreliable or prone to bias.

The low AMSTAR-2 scores were predominantly driven by key deficiencies, chiefly the lack of an a priori registered protocol and the failure to adequately address the impact of potential publication bias. This observation is consistent with previous methodological evaluations of complementary medicine systematic reviews, which have identified inadequate protocol registration, incomplete reporting, and insufficient assessment of publication bias as common methodological weaknesses.^70-72 These systemic flaws undermine the reliability of the evidence, regardless of the reported statistical significance. This finding carries significant implications for clinical practice guidelines (e.g., NCCN, SIO), as caution must be exercised when incorporating evidence derived from methodologically flawed SRs. Future review authors must stringently resolve these issues by adhering to PRISMA reporting standards and mandatory prospective protocol registration to improve scientific rigor.

These results underscore both the potential of acupuncture-related therapies to address specific breast cancer symptoms and the ongoing methodological weaknesses that constrain certainty in the evidence base. Notably, nearly one third of the SRs addressed general supportive care or broad side effect management rather than discrete symptom domains, reflecting both the complexity of symptom clusters in oncology and the lack of harmonized outcome reporting.

Methodological Justification and Research Landscape

The decision to restrict this evidence map exclusively to systematic reviews incorporating meta-analysis was a deliberate methodological choice. This approach was implemented to eliminate the inherent heterogeneity and subjective interpretation often associated with non-quantitative synthesis, thereby providing a more objective assessment of clinical efficacy. By focusing on studies that report a clear effect size or quantitative direction of effect, we significantly enhance the interpretability and clinical utility of the resulting evidence map, allowing researchers and clinicians to more readily identify high-signal areas of research.

Furthermore, the visualization provided by the evidence map clearly demonstrates significant research overlap, particularly within high-frequency domains like hot flashes and CINV. The recurrent publication of SRs covering nearly identical primary studies raises concerns about research redundancy and the efficient use of resources. The increasing number of systematic reviews in this field reflects the growing interest in acupuncture as supportive cancer care but also highlights concerns regarding research redundancy, which have been noted in previous evaluations of evidence synthesis methodology.^19,73 Notably, psychological symptoms such as anxiety and depression were not represented among the systematic reviews included in this evidence map. This reflects the evidence captured within our predefined search strategy and eligibility criteria rather than the absence of research in this area. Recent systematic reviews suggest that evidence on psychological outcomes in breast cancer is emerging and should be considered in future updates of this evidence map. This evidence map serves a vital function by clarifying the existing literature, which can help guide research funding bodies and future authors to prioritize neglected areas (white space on the map) and avoid duplicating efforts in already well-covered, albeit low-quality, domains.

Strengths and Limitations

A key strength of this study is the evidence mapping approach, which provides a broad overview of the scope, quality, and direction of evidence rather than limiting focus to a single outcome. By categorizing interventions and outcomes systematically, this map highlights areas of research concentration and identifies gaps that remain underexplored. Additionally, integrating AMSTAR-2 appraisal into the visualization allows readers to judge both the quantity and reliability of evidence simultaneously.

However, several limitations must be acknowledged. First, the underlying SRs were of generally low methodological quality, with frequent deficiencies in protocol registration, justification of excluded studies, and consideration of publication bias. Second, many SRs suffered from overlap in primary studies, which may overrepresent evidence for certain outcomes (e.g., hot flashes, pain). Third, heterogeneity in interventions (e.g., manual acupuncture, electroacupuncture, acupressure, moxibustion) and outcome definitions limited the ability to draw firm conclusions across domains. Due to substantial heterogeneity in outcome measures, effect metrics, and reporting across systematic reviews, effect sizes could not be consistently synthesized or incorporated into the evidence map. In particular, acupoint injection differs substantially from needle-based acupuncture and acupoint-based physical therapies in terms of mechanism of action, regulatory oversight, and safety considerations. Although included to reflect real-world integrative oncology practice, evidence from acupoint injection SRs may not be directly generalizable to settings where such interventions are regulated as pharmacological agents rather than acupuncture-related therapies. An additional limitation is the potential overlap of primary studies across included systematic reviews. Because the same primary trials may be included in multiple reviews, the descriptive classification of effect direction may inadvertently amplify apparent evidence signals. As a formal overlap assessment (e.g., Corrected Covered Area) was not conducted, the evidence map should be interpreted as a descriptive, hypothesis-generating overview rather than conclusive evidence of intervention effectiveness. Future overviews should incorporate formal overlap assessments to improve methodological rigor. Finally, several SRs categorized as “general supportive care during chemotherapy” relied on heterogeneous and sometimes non-validated composite outcomes (e.g., overall effective rate, immune markers), which should be interpreted carefully and should not be equated with validated symptom-specific or patient-reported outcomes. The outcomes included in this evidence map reflect those reported in the original systematic reviews and may comprise a mixture of validated patient-reported measures and composite or surrogate outcomes. This heterogeneity should be considered when interpreting the findings. In addition, safety outcomes were not consistently reported across the included systematic reviews, limiting our ability to draw firm conclusions regarding adverse events. Future research should incorporate more rigorous and standardized reporting of safety data. Finally, because literature searches were conducted up to April 24, 2025, subsequently published systematic reviews were not captured and should be incorporated in future updates of this evidence map.

Implications for Practice and Research

Despite limitations, the evidence suggests that acupuncture-related therapies may offer meaningful benefits for breast cancer patients, particularly for hot flashes, lymphedema and musculoskeletal pain associated with aromatase inhibitor therapy. Clinicians may consider these interventions as part of integrative supportive care, in line with existing guideline recommendations, while recognizing the limitations of the evidence base.

Conclusion

This evidence map demonstrates that acupuncture and related therapies are widely studied as supportive care options for breast cancer–related symptoms. However, most SRs were of low or critically low quality, and findings remain inconsistent. Future research should prioritize high-quality, symptom-specific trials and SRs to strengthen the evidence base and better inform clinical practice and guideline development.

ORCID iD

Tae-Young Choi https://orcid.org/0000-0003-0638-2153