Effect of Chinese Traditional Wushu on Cancer-Related Fatigue, Sleep Quality and Upper Limb Dysfunction of Breast Cancer Survivors: A Systematic Review and Meta-Analysis.

Objective: This study is aimed at evaluating the effect of Chinese traditional Wushu (CTW) on cancer-related fatigue (CRF), sleep quality, and upper limb dysfunction. Data Sources. We searched studies containing randomized controlled trials up to July 2021 in PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, and China Biological Medicine on this topic.
Methods: A randomized controlled trial of CTW on major outcome indicators such as CRF, sleep quality, and upper limb dysfunction of breast cancer survivors. Study screening, data extraction, and risk of bias assessment were performed independently by two reviewers. Meta-analysis was conducted with Stata 16.0 software. The quality of the evidence was assessed by the Cochrane Collaboration Risk of Bias (ROB2.0).
Results: Eighteen studies met the requirements for meta-analysis (n = 1331). We found that CTW has no obvious effect on improving breast cancer survivors' CRF (SMD = -0.733; P = 0.059; I 2 = 89.3%), but it can effectively improve their sleep quality (WMD = -2.266; P = 0.022; I 2 = 99.2%) and upper limb dysfunction (SMD = 1.262; P ≤ 0.001; I 2 = 88.5%).
Conclusion: Although more studies on this topic are needed to prove the effectiveness of this method, the results of our review show that CTW is significantly helpful for better sleep and upper limb dysfunction. But the effects on CRF will need to be confirmed further. Implications for Cancer Survivors. In the future intervention process, to verify the effectiveness of CTW on improving CRF for breast cancer survivors, it would be suggested to pay close attention to breast cancer survivors' response to exercise, achieve regular follow-up, strictly conduct the intervention scheme on the premise of ensuring absolute security, and reduce the loss of intervention objects.

1. Introduction

Breast cancer is one of the most common malignancies in women worldwide. According to the latest global cancer burden data for 2020 released by the International Agency for Research on Cancer (IARC) of the World Health Organization, there were 19.26 million new cancer cases worldwide in 2020, of which 2.26 million were breast cancer, making it the first majority cancer globally [1]. Patients with breast cancer are treated mainly by surgery. But postoperative complications and adverse drug reactions after chemotherapy will affect blood circulation and lymph system, which may cause swelling and pain of the upper limb, shoulder stiffness, and other upper limb dysfunction, leaving a serious impact on the patient's life [2-4]. Cancer-related fatigue (CRF) is one of the most common symptoms of cancer survivors. It is related to the tumor type and treatment, with the characteristics of rapid onset, long duration, harsh severity, and unpredictability. Therefore, to reduce CRF, effective diagnosis and interventions are particularly important [5, 6]. In addition, the fatigue level of breast cancer survivors is significantly higher than that of other cancer patients, which seriously affects the survival quality of patients. Clinically, fatigue has become an important influencing factor for treatment and recovery [7, 8]. The incidence of insomnia in breast cancer patients is the highest among all cancer types, and the incidence rate is 60% 2 months after surgery [9]. Their sleep disorders often interact with anxiety, fatigue, pain, and other symptoms, causing immunosuppression and endocrine dysfunction, which seriously affects their sleep quality [10]. The Chinese traditional Wushu (CTW) is the sum of the various styles of martial arts that have been developed by the Chinese people over a long period and nourished by traditional Chinese culture, with boxing as the main carrier, with the main purpose of improving the ability to attack and defend, with the emphasis on the combination of form and spirit, the combination of fighting and practice, and the unity of internal and external training [11-13]. CTW includes TaiChi, Baduanjin Qigong, and Fitness Qigong, which together with Chinese competitive martial arts form the Chinese martial arts [14, 15]. CTW is the safest and most effective nonmedication treatment for CRF and upper limb dysfunction. CTW including TaiChi, Fitness Qigong, and Baduanjin Qigong is easy to learn, whose intensity can be maintained at a stable level slightly higher than the anaerobic threshold. These sports involve movements of the muscles and joints of the whole body, especially the spiral circular movement of upper limbs which is suitable for postoperative rehabilitation of breast cancer survivors. It can produce beneficial changes to the composition of the body and blood fats of the patients to improve the physical condition of patients and improve their quality of life [2–4, 16]. Clinical research at home and abroad showed that CTW can effectively improve CRF, sleep quality, and upper limb dysfunction. Although other aerobic sports also have a positive effect on upper limb dysfunction of breast cancer survivors, most patients can not enjoy the pleasure of physical exercise because of passive participation. Therefore, the effect of aerobic sports is not ideal. And most of the recent studies on this topic mainly focused on the impact of patients' life quality; few specially analyzed the effects of CTW on CRF, sleep quality, and upper limb dysfunction. Others had no specific quantitative statistical results, or the results in their studies needed to be updated. Therefore, this article is intended to research on the effect of CTW on CRF, sleep quality, and upper limb dysfunction.

2. Materials and Methods

2.1. Search Criteria

We selected random words on this topic through subject word extraction in the PubMed database to expand the retrieval scope. Then, using computer retrieval and artificial retrieval method, we collected studies containing randomized controlled trials (RCT) up to July 2021 in Chinese and English by searching subject words combined with random words in PubMed, Embase, Web of Science, China National Knowledge Infrastructure (CNKI), Wanfang database, and China Biological Medicine. The random words combined with breast cancer are “breast cancer,” “cancer, breast,” “breast neoplasm,” “neoplasm, breast,” “breast tumors,” “breast tumor,” “tumor, breast,” “tumors, breast,” “neoplasms, breast,” “breast carcinomas,” “carcinoma, breast,” and “carcinomas, breast.” The random words combined with CRF are “fatigue,” “cancer-related fatigue,” and “CRF.” The random words combined with sleep quality are “sleep quality” and “sleep disorder.” The random words combined with upper limb dysfunction are “disfunction,” “upper limb dysfunction,” and “Upper limb dysfunction after breast cancer surgery.” And the random words combined with CTW are “Chinese traditional wushu,” “mind-body exercise,” “TaiChi,” “Qigong,” “Baduanjin Qigong,” and “Liuzijue Qigong.” Studies retrieval were as follows: (1) Studies on this topic were searched in Cochrane and JBI library. (2) Subject words were combined with random words according to the actual situation to identify the retrieval scope and specify the standard studies. (3) Included studies were further screened by matching their abstract content to our inclusion criteria. And full texts of the studies by the criteria were searched. (4) The references of the included studies were selected to find more standard studies. WHN and RSY completed the research process separately. Meeting and consulting with another author (QYF) solved any disagreements in these regards. Our research was registered in PROSPERO (CRD42021269774) on 24 June 2021 (Table S2–S4>).

2.2. Inclusion Criteria

The following are the inclusion criteria:

Study designs: RCT was conducted to evaluate the specific impact of CTW on breast cancer survivors CRF, sleep quality, and upper limb dysfunction.

Study participants: patients diagnosed pathologically or cytologically as breast cancer survivors without limitations on age and case resources who suffered the CRF, sleep disorder, and upper limb dysfunction.

Intervention methods: patients in the intervention group participated in CTW (including TaiChi, Fitness Qigong, Baduanjin Qigong, and Liuzijue Qigong) which were well organized to improve CRF, sleep quality, and upper limb dysfunction and also received the treatment of routine rehabilitative training, common nursing, and cognitive behavioral therapy, while patients in the same period of the control group were treated only through routine rehabilitative training, common nursing, and cognitive behavioral therapy with no CTW intervention.

Outcomes and scales: main outcomes are CRF, sleep quality, and upper limb dysfunction. CRF was evaluated by the revised Chinese version of the Brief Fatigue Inventory (BFI), Fatigue Symptom Inventory (FSI), and revised Piper Fatigue Scale (PFS-R). Pittsburgh Sleep Quality Index (PSQI) was adopted to assess sleep quality. And upper limb dysfunction was scored by Constant-Murley shoulder score and Neer shoulder score.

2.3. Exclusion Criteria

The following are the exclusion criteria: nonrandomized controlled trials, cohort studies or case-control studies, animal experiments, repeated studies, studies without eligible outcomes, and studies including relapsed or metastatic breast cancer survivors.

2.4. Data Extraction

All included studies provided complete cases of breast cancer survivors, their CRF score before the intervention, and other data. Two authors (WHN and RSY) extracted data separately from the included studies for analysis, resolved any disagreement through discussion and reached a consensus, or requested an opinion of a third author (QYF). The extracted outcomes from RCT included title, author, publication year, publication country, basic information of study participants, intervention types and measures, study duration, frequency and times, the mean and standard deviation of outcomes, and study results. If the standard deviation is not provided in the original text, we will calculate it based on the 95% CI provided through the method in the system evaluation manual.

2.5. Study Quality Assessment

Two authors (GEY and YZ) evaluated the quality of the included studies using the Cochrane Collaboration Risk of Bias (ROB2.0) for assessing the risk of bias recommended. The Cochrane Tool allowed for analyzing the following groups: random sequence generation, allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and other (analysis for intention to treat and compliance). For each bias group, it was possible to assign a value of “high,” “low,” or “unknown” risk of bias when it was not specified if a specific bias was present or not. And two authors decided through discussion whether to include or eliminate certain studies. Any disagreements in the evaluation process were resolved by the third author (QYF).

2.6. Statistical Analysis

We applied Stata 16.0 software to conduct the meta-analysis and used standardized mean difference (SMD) as the statistic for continuous data. A chi-square test was adopted for measuring heterogeneity, and I2 was used to evaluate the heterogeneity. When there is no statistical heterogeneity between studies (P > 0.1, I2 < 50%), a fixed-effects model was used. On the contrary, we analyzed the sources of clinical heterogeneity by three sensitivity analysis methods: changing the combined effect size model, removing the study with the largest weight, and eliminating each study separately to monitor the changing of effect quantity and P value. A random-effects model was chosen when clinical judgment was made that there was consistency between groups that needed to be combined. And subgroup analysis was used for analyzing the source of significant heterogeneity. If P < 0.1 and the source of heterogeneity cannot be judged, we used descriptive analysis rather than meta-analysis. The handbook of Cochrane recommends testing for funnel plot asymmetry “As a rule of thumb, tests for funnel plot asymmetry should be used only when there are at least 10 studies included in the meta-analysis, because when there are fewer studies the power of the tests is too low to distinguish chance from real asymmetry [17].

3. Results

3.1. Search Findings

Our search yielded 1042 studies via databases and registers. We removed 286 duplicate records, 57 records for no full text, 26 records for no retrieval, and 655 records for other reasons. And 18 studies were included for meta-analysis. Figure 1 shows the flowchart with the study selection process.

Figure 1

Flow diagram of study selection.

3.2. Characteristics of the Included Studies

18 studies were included in which there was a total of 1331 patients. And the sample sizes ranged from 8 to 134 patients. Interventions for the CTS group are TaiChi, Fitness Qigong, Baduanjin Qigong, and Liuzijue Qigong. PSQI was adopted for 8 studies, Constant-Murley shoulder score for 5 studies, Neer shoulder score for 2 studies, BFI for 2 studies, FSI for 2 studies, and PFS-R for 1 study. The duration of CTS ranged from 6 to 60 weeks. Table 1 shows the characteristics of the included studies.

Table 1

Characteristics of the included studies.

Included studies	Source	Number of cases		Age		Intervention		Intervention duration	Outcomes
		IG	CG	IG	CG	IG	CG
Irwin et al. [18]	USA	45	45	42-83	42-83	TaiChi	RRT	12 weeks	PSQI
Liu et al. [19]	China	4	4	≥18	≥18	Fitness Qigong	RRT	12 weeks	PSQI
Irwin et al. [20]	USA	45	45	42-83	42-83	TaiChi	CBT	60 weeks	PSQI
Wang [21]	China	45	41	35-63	35-63	TaiChi	RRT	24 weeks	PSQI
Wu et al. [22]	China	33	35	36-70	36-70	Baduanjin Qigong	RRT	12 weeks	PSQI
Cheng et al. [23]	China	27	26	≥55	≥55	TaiChi	Common nursing	12 weeks	PSQI
Chen et al. [24]	China	49	47	25-64	25-64	Fitness Qigong	RRT	12 weeks	BFI, PSQI
Larkey et al. [25]	USA	30	30	40-75	40-75	TaiChi, Fitness Qigong	Common nursing	12 weeks	FSI, PSQI
Thongteratham et al. [26]	Thailand	15	15	30-60	30-60	TaiChi, Fitness Qigong	Common nursing	12 weeks	FSI
He et al. [27]	China	31	33	29-62	29-62	Fitness Qigong, Liuzijue Qigong	Common nursing	12 weeks	BFI
Han et al. [16]	China	23	21	18-60	18-60	TaiChi	RRT	12 weeks	PFS-R
Wang et al. [4]	China	62	58	28-65	28-65	TaiChi	RRT	12 weeks	Constant-Murley
Wang et al. [28]	China	63	71	28-65	28-65	TaiChi	RRT	12 weeks	Constant-Murley
Sun et al. [29]	China	35	41	28-53	28-53	TaiChi	RRT	12 weeks	Constant-Murley
Lv et al. [30]	China	50	49	32-65	32-65	TaiChi, Baduanjin Qigong	RRT	12 weeks	Constant-Murley
Lv et al. [3]	China	29	28	32-60	32-60	TaiChi	RRT	6 weeks	Constant-Murley
Xiao et al. [31]	China	33	33	64-77	65-77	TaiChi	CBT	24 weeks	Neer
Wang et al. [32]	China	44	46	≥18	≥18	TaiChi	RRT	12 weeks	Neer

PSQI: Pittsburgh Sleep Quality Index; BFI: Brief Fatigue Inventory; FSI: Fatigue Symptom Inventory; PFS-R: revised Piper Fatigue Scale; Constant-Murley: Constant-Murley shoulder score; Neer: Neer shoulder score; IG: intervention group; CG: control group; RRT: routine rehabilitative training; CBT: cognitive behavioral therapy.

3.3. Quality Assessment

The results of Cochrane's risk of bias assessment (Figures 2 and 3) showed that for most studies, the overall risk of bias was low. Among them, 12 of the studies (67%) described the generation of random sequences in detail. However, there are 6 studies (33%) to mention it is RTC. In fact, there is no detail to support it to be a real RTC, so they are classified as high risks. In the categories “Timing of identification or recruitment of participants” and “Deviations from the intended interventions,” 27 (75%) trials were assessed as low risk, 8 (22%) trials as unclear risk, and 1 (3%) trials as high risk, which was related to the lack of accurate information on blinding. The low-risk categories in 39%–78% of the studies were “Selection of the reported result,” “Measurement of the outcome,” and “Missing outcome data”; the remaining studies were judged to be of unclear risk and high risk due to insufficient information on the methods used by researchers to randomly assign participants to groups and in reporting all predefined results. Due to the limited number of studies, it was impossible to explore the existence of publication bias.

Figure 2

Risk of bias graph per type of bias assessed.

Figure 3

Risk of bias summary for the studies assessed.

3.4. Impact of CTW on CRF

BFI, FSI, and PFS-R were applied for 5 studies to score the impact of CTW on CRF. We analyzed the fatigue comparison results between the intervention group and control group (random model I2 = 89.3% > 50%, X2 = 37.49, P ≤ 0.001). The results showed that the difference in reduced value of fatigue scores between intervention group and control group had no statistical significance (SMD = −0.733, Z = −1.886, P = 0.059 > 0.05, 95%CI = −1.495 ~ 0.029). (Figure 4).

Figure 4

Impact of CTW on CRF.

We performed subgroup analysis stratified by the CRF scoring system to analyze the potential source of heterogeneity. The results showed that the added value difference of fatigue scores provided by BFI between the intervention group and control group had no statistical significance (SMD = 0.066, Z = 0.413, P = 0.679 > 0.05, 95%CI = −0.245 ~ 0.376). But the difference in fatigue reduction provided by FSI between both had statistical significance (SMD = −1.145, Z = −2.413, P = 0.016 < 0.05, 95%CI = −2.075 ~ −0.215). (Figure 5).

Figure 5

Subgroup analysis of the impact of CTW on CRF.

3.5. Impact of CTW on Sleep Quality

The impact of CTW on sleep quality was evaluated and scored by PSQI in 8 studies. We analyzed the comparison results of sleep quality scores between the CTW group and control group (random model I2 = 99.2% > 50%, X2 = 868.21, P ≤ 0.001). And the results turned out to show that there was statistical significance in the different reduction of PSQI scores between both groups (WMD = −2.266, Z = −2.284, P = 0.022 < 0.05, 95%CI = −4.211 ~ −0.321) (Figure 6).

Figure 6

Impact of CTW on sleep quality.

3.6. Impact of CTW on Upper Limb Dysfunction

Both Constant-Murley and Neer shoulder scores were adopted to score the impact of CTW on upper limb dysfunction. We analyzed the comparison results of upper limb dysfunction scores between the CTS group and control group (random model I2 = 88.5% > 50%, X2 = 52.32, P ≤ 0.001). And the results showed that there was statistical significance in the added value of upper limb dysfunction scores between both groups (SMD = 1.262, Z = 4.845, P ≤ 0.001, 95%CI = 0.752 ~ 1.773) (Figure 7).

Figure 7

Impact of CTW on upper limb dysfunction.

4. Discussion

This study is the first systematic review and meta-analysis that combines CTW with CRF, sleep quality, and upper limb dysfunction of breast cancer survivors, to evaluate the changes of indicators related to upper limb dysfunction, for instance, CRF index, PSQI, Constant-Murley shoulder score, and Neer shoulder score.

The results show that CTW can improve the CRF of breast cancer survivors, mainly related to the following three aspects. First, it can work by regulating levels of IL-6, TNF-α, and IL-1β. Wood et al. suggested that tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) might cause CRF symptoms and interleukin-6 (IL-6) can effectively inhibit proinflammatory cytokines such as TNF-α and IL-1β and expose the body to the environment of anti-inflammatory cytokines [33]. Meanwhile, physical exercise can make skeletal muscles produce a large amount of IL-6, increasing the concentration of IL-6 in serum. After low-to-medium intensity exercise, IL-6 level increases while TNF-α and IL-1β levels decrease, and CRF is reduced [34, 35]. In addition, studies have shown that CTW can promote the production of endorphin and catecholamines that make people physically and mentally happy [36], which can effectively regulate the patient's mood and improve their fatigue caused by CRF [37]. Secondly, it may be related to mitochondrial damage reduction and mitochondrial protection. Mitochondria are important sites for energy metabolism and aerobic respiration [38]. Mitochondrial dynamics are involved in the regulation of adenosine triphosphate (ATP) synthesis, oxidative stress, and apoptosis and are closely related to breast cancer invasion and metastasis [5, 39]. A study has shown that after physical exercise, plasma ATP levels increased, mitochondrial membrane potential (MMP) increased, and glutathione (GSH) synthesis increased while malondialdehyde (MDA) synthesis decreased, and moderate-intensity exercise can alleviate CRF [40, 41]. Finally, it can restore the body function of breast cancer survivors by dredging the meridians. Traditional Chinese medicine (TCM) believes that CRF is a variety of chronic weakness symptoms mainly caused by the decline of visceral function, and the insufficiency of qi, blood, and yin-yang, which are impaired and difficult to recover [42], cooperating with breathing and meditation during exercise practice to achieve the functions of physical and mental regulation. In the practice of the movements of “brushing knee and twisting step,” it can increase the strength of the upper and lower limb muscle groups (biceps, finger extensor, flexor, gluteus maximus, etc.), at the same time dredge the upper and lower limbs corresponding to the hand three yang meridian, hand three yin meridian, and foot three yang meridian, foot three yin spleen meridian, and thus improve the function of various visceral organs, which is beneficial for breast cancer survivors to recover physical function [43-47]. CTW can improve the sleep quality of breast cancer survivors, mainly related to the following three aspects. First, it can work through the synthesis and release of neurotransmitters such as serotonin and dopamine. Studies have shown that CTW can significantly improve the intracerebral activation levels of neurotransmitters such as 5-hydroxytryptamine, norepinephrine, and dopamine; increase cerebral blood flow; accelerate metabolism; promote the release of endorphins; and thus improve the sleep quality of patients [48-51]. Secondly, the reason it works may be related to the increase of melatonin secretion. Melatonin is a neuroendocrine hormone secreted by the epiphysis, which plays a particularly important role in regulating human biorhythm and sleep [52]. A study has shown that after CTW intervention, serum melatonin concentration was significantly increased, and significant differences were found in sleep efficiency, sleep quality, and sleep latency, which had a good effect on improving the sleep quality of breast cancer survivors [53-57]. Finally, it can work by regulating neural excitation. In practice, the patient is required to be in a peaceful mind. The movement practice of “stretching left and right arms like a bow” can generate an energy stream through physical activity. The limbs stretch and flex alternately, which can suppress the excitability of the central nervous system in the brain; stimulate the parasympathetic nerve; make patients feel calm, comfortable, and delighted; and thus improve the patient's sleep quality [45, 58–60]. The ability of CTW to improve the dysfunction of the affected limb in breast cancer patients is mainly related to movement characteristics. The spiral circular movements of TaiChi are flexible, stable, slow, and coherent, which can involve the whole body muscles and joints in movements. The joints and bones rotate with the traction of the muscles, which plays a role of massage. It is not only conducive to the recovery of shoulder joint function but also conducive to the promotion of lymphatic reflux and the prevention of lymphedema, fluid accumulation, and flap necrosis in the upper limbs caused by breast cancer surgery [61, 62]. A movement of Baduanjin—“Clenching fist with glaring eyes to increase strength”—requires the fingers to exert force, which can fully exercise the muscle group of the forearm and hand [63, 64].

The results of this study suggest that CTW can improve the CRF of breast cancer survivors, and similar results have been obtained in previous studies. Larkey et al. [6] and Thongteratham et al. [26] compared the scores of FSI (Fatigue Symptom Inventory) and conducted 12-week TaiChi and Qigong intervention on breast cancer survivors. The results showed that there was a significant interaction between the intervention group and intervention time in FSI, and there was a great decline of FSI after the intervention and during 3-month follow-up, which was considered a medium effect according to the general guideline for effect size, indicating that CTS had a beneficial effect on improving CRF in breast cancer survivors. Chen et al. [24] and He et al. [27] used BFI for evaluation and conducted a 12-week Qigong intervention on breast cancer survivors. After the intervention, He et al. found that the difference in BFI scores is statistically significant, and the study showed that the intervention was effective in alleviating CRF, which fully proved the effect of Qigong on improving CRF in breast cancer survivors. Chen et al. also conducted the same intervention, but there was no significant difference. The reason for the difference may be that the author did not monitor the intervention group actively and effectively, which caused the intervention process to be affected by the external environment, thus failing to achieve the intervention effect. Han et al. [16] used PFS-R to evaluate the fatigue condition of breast cancer survivors after 12 weeks of TaiChi intervention. The results showed that there were significant differences between the total score of CRF and the score of each dimension after the intervention. It was considered that TaiChi has high compliance, which was easy to meet the exercise requirements of CRF, and could effectively alleviate fatigue. Therefore, it is worthy of clinical application. CTW can improve the sleep quality of breast cancer survivors. In these studies [18, 19, 22, 23, 25], 12-week TaiChi and Fitness Qigong intervention was conducted on breast cancer survivors, which found that their total scores of PSQI were reduced to varying degrees. The results showed that TaiChi and Qigong had positive effects on the sleep quality of breast cancer survivors. Chen et al. [24] also conducted a 12-week Fitness Qigong intervention on breast cancer survivors, but the results showed no significant difference, possibly because of the author's failure to actively monitor the intervention group, which was affected by the social environment, thus affecting the effect of the intervention. Irwin et al. [20] and Wang [21] conducted 24 and 60 weeks of intervention on breast cancer survivors, respectively. Wang found that the total score of PSQI was significantly different before and after the intervention. Moreover, the overall sleep quality improved to a higher level, and the more times the patients exercised, the lower PSQI and better sleep quality they would get. However, Irwin et al. found no significant difference after 60 weeks of intervention, mainly due to the long period of the intervention, which led to the serious loss of test objects in the TaiChi intervention group, and few people adhered to the last, while this situation did not occur in the control group. When different proportions of test objects in the intervention group and control group quitted, it would lead to the deviation of the supposed results [65]. CTW can improve the upper limb dysfunction of breast cancer patients. In several studies, the Constant-Murley shoulder score was used to evaluate the recovery of upper limb function. Conducting 6-12 weeks of TaiChi and Fitness Qigong intervention on breast cancer survivors, the results showed that TaiChi and Fitness Qigong had significant advantages in rehabilitation training for the upper limb dysfunction of breast cancer survivors, and all index scores were better than those of the control group. When conducting TaiChi intervention on breast cancer survivors, Wang et al. [28] and Sun et al. [29] found that the items of pain recovered significantly after 4 weeks of intervention, but the items of muscle strength recovered relatively poorly, while the daily living ability and the range of motion were better than those of the control group. After 12 weeks of intervention, the patients' upper limb function was further recovered and the pain was almost gone. The scores of other items in the intervention group were significantly better than those in the control group. In 2015, Lv et al. [30] conducted TaiChi and Fitness Qigong intervention on breast cancer survivors for 12 weeks. After 4 weeks, compared with the control group, the intervention group had a more significant effect on improving the upper limb dysfunction, and the pain-relieving was the most obvious. After 12 weeks, the recovery of the patients' function was further improved, and the pain only showed stabbing pain. The scores of the intervention group were higher than those of the control group. Three years later, Lv et al. [3] conducted a 6-week TaiChi intervention on breast cancer survivors, and the results showed that the score of each item improved significantly which includes the daily living ability and joint function, and the pain-relieving was the most obvious. After the intervention, it was found that the scores of various indexes in the intervention group were significantly better than those in the control group, which showed great advantages and indicated that CTW had extensive feasibility and scientificity. Xiao et al. [31] and Wang et al. [32] used Neer shoulder score to evaluate the recovery of upper limb function of breast cancer survivors and conducted 12 and 24 weeks of TaiChi intervention on breast cancer survivors, respectively. The results showed that TaiChi can effectively improve the function of the shoulder joint, and the effect was more significant than that of the control group with the longer intervention time, which indicated that TaiChi can promote the recovery of upper limb function effectively. In comparison, the Constant-Murley shoulder score is more recommended for its completeness to studies of upper limb dysfunction.

The literature included in this study has some limitations, and the studies involved in our study have heterogeneity in samples and methodology. Also, the intervention time was not unified, causing great differences in the rehabilitation period of the research objects, which may be related to the form, frequency, and duration of CTW intervention. However, two methods were used for sensitivity analysis in this meta-analysis (Figure S1–S3), and it was found that the results were stable and reliable; therefore, the study results were hardly affected by heterogeneity. Moreover, the sample size of 5 items included in this study was less than 60 cases, and no sequential analysis was conducted to test whether there were false-positive conclusions. In addition, the evaluation methods of outcome indicators are different, and the evaluation standards of different scales are also different.

To sum up, the results of this study show that CTW can be considered an effective intervention measure, which has a good effect on improving sleep quality and upper limb dysfunction, but there is a divergence of the effect of improving CRF. Although most of the research results show positive effects, a few studies show no significant differences. In the future intervention process, to verify the effectiveness of CTW on improving CRF for breast cancer survivors, it would be suggested to pay close attention to patients' response to exercise, achieve regular follow-up, strictly conduct the intervention scheme on the premise of ensuring absolute security, reduce the loss of intervention objects, and ensure the preciseness, rationality, and scientificity of the intervention.

5. Clinical Message

There is strong evidence that CTS is more effective than common nursing for improving sleep quality and upper limb dysfunction of breast cancer survivors

There is conflicting evidence that CTS is more effective than common nursing for improving CRF of breast cancer survivors