Abstract

Introduction

Among the cancers that threaten the health and lives of women, breast cancer ranks first in the world (1). Indeed, the incidence of breast cancer ranks first in most countries (i.e., in 159 of 185 countries) (1). China has the highest incidence of (17.6%), and mortality rate (15.6%) for, female breast cancer in the world (2). With advancements in diagnosis and treatment, the survival rate of breast cancer patients is increasing year by year, but the 5-year survival rate is still as high as 90% (3). Thus, while the life expectancy of breast cancer patients has been prolonged, patients with breast cancer are prone to anxiety, depression, fatigue, and other psychological problems during treatment, which also affect their quality of life (QoL) (4,5).

QoL has become an important criteria for evaluating the overall treatment of cancer. Depression and anxiety are common complications among breast cancer patients. Study has shown that depression and anxiety negatively affect the treatment, relapse, and all-cause mortality of breast cancer patients (6). Thus, improving patients’ psychological state to increase the cure rate has become a popular area of clinical research (7).

Patients with breast cancer have expressed more and more interest in using complementary and integrative therapies as supportive care to restore their physiological functions and adjust their mental state (8,9). Complementary and comprehensive therapies include a variety of activities, such as relaxation approaches, meditation, deep breathing, guided imaging, and stress management interventions (10). Muscle relaxation training is an economical and convenient intervention method. Progressive relaxation training is the most commonly used relaxation training method at present, which has the characteristics of strong operability, good application effect and easy acceptance. Patients through conscious control of the body muscle repeated contract-relaxation cycle process, to achieve the effect of gradual relaxation of the whole body (11,12). However, there is insufficient evidence to support the use of muscle relaxation training in an oncology setting.

Complementary and integrative therapies are becoming more and more commonly used in medical practice, and muscle relaxation training is one of the most promising integrative breast cancer treatments. However, at present, this therapy has been applied in coronary heart disease, diabetes, hypertension, asthma, myocardial infarction and other acute and chronic diseases, which has been proved to help patients reduce negative emotions and improve their quality of life to a certain extent. But the study concluded that the treatment did not work as well as expected in breast cancer patients

This study conducted a systematic review and meta-analysis based on randomized controlled trials (RCTs) or quasi-RCTs to evaluate the effects of muscle relaxation training on the psychological health and QoL of breast cancer patients. This study sought to provide evidence for choosing active care in clinical practice to produce improvements in the psychological state and QoL of breast cancer patients.

We present the following article in accordance with the PRISMA reporting checklist (available at https://tcr.amegroups.com/article/view/10.21037/tcr-22-428/rc).

Methods

Results

Article selection process and results

In total, 572 studies were retrieved, and after review, 13 RCT or quasi-RCT trials, comprising a total of 1,355 patients, were finally included in the meta-analysis (11,16-27). The article screening process and results are shown in Figure 1.

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Figure 1

Article selection process and results.

The basic characteristics of the included studies and the results of the risk assessment of bias

The included studies were published from 2005 to 2021, and comprised a total of 1,355 patients (679 in the experimental group and 676 in the control group) (17,21,25). Of the articles, 3 were quasi-RCTs. A random sequence was generated in the order of admission time (17). One study was an open-label trial. The basic characteristics of the included articles are set out in Table 1.

Table 1

Basic characteristic of the included studies

Study	Country	N (T/C)	Intervention		Cure time	Marital status		Age (T/C) (year, mean ± SD)	Education level
			T	C		T [N]	C [N]		T [N]	C [N]
Kovačič Tine 2011 (16)	Slovenia	16/16	Yoga + routine care	Routine care	4 weeks	Single [1], married [11], widowed [3], divorced [1]	Single [0], married [13], widowed [2], divorced [1]	50.1±9.37/50.1±8.31	High school [8], college [8]	High school [8], college [8]
Demiralp Meral 2010 (11)	Turkey	14/13	PMRT + routine care	Routine care	8 sessions		58 [48–75]/55 [40–73]
Kurt Berna 2018 (17)	Turkey	25/24	Relaxation exercises	Routine care	8 times	Single [7], married [18]	Single [5], married [19]	50.7±9.1/52.4±10.0	Primary school [10], elementary school [4], high school [6], college or more [5]	Primary school [11], elementary school [5], high school [4], college or more [3]
Pruthi Sandhya 2012 (18)	USA	15/15	Yoga	Routine care	8 weeks		42.91±10.1/44.00±7.2
Vuttanon Nuttamon 2019 (19)	Thailand	48/48	PMRT	Routine care		Single [16], married [27], widowed [5]	Single [5], married [35], widowed [8]		None [1], primary school [18], secondary school [7], college or more [22]	None [2], primary school [15], secondary school [14], college or more [17]
Yoo Hee J 2005 (20)	South Korea	30/30	PMRT + GI	Routine care	6 sessions	Single [3], married [25], widowed [2]	Single [2], married [26], widowed [2]		11.9±3.2 (year, mean ± SD)	11.67±4.8 (year, mean ± SD)
Chun-Li Song 2019 (27)	China	30/30	Relaxation exercises	Routine care	5 weeks
Linnan Yuan 2017 (26)	China	100/100	PMRT	Routine care	5 weeks		47.59±10.62/48.61±10.35
Xu-Yan Xi 2019 (25)	China	43/43	PMRT + routine care	Routine care	5 weeks
Min Chen 2021 (21)	China	51/52	PMRT + routine care	Routine care	6 weeks			47.2±2.5/47.1±3.1	Junior high school and below [12], high school [24], junior college or more [15]	Junior high school and below [14], high school [21], junior college or more [17]
Ningrui Hou 2017 (23)	China	200/200	PMRT + routine care	Routine care	5 weeks		52.5±2.2/52.4±1.6
Wei Jiao 2016 (24)	China	50/50	PMRT + routine care	Routine care	4 weeks
Yuhua Liu 2020 (22)	China	57/55	PMRT + routine care	Routine care	5 weeks

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N, number of cases; T, Trial group, C, Control group; PMRT, progressive muscle relaxation training; GI, guided imagery; SD, standard deviation.

The results of the risk of bias assessment are shown in Table 2, Figure 2, and Figure 3. In the studies included in the meta-analysis, the risk of sequence generation and allocation of the 11 articles was low (21,25). The 2 studies that generated random sequences in the order of odd and even numbers and admission time had a high risk of bias. In general, the risks of implementation bias and detection bias were low. All the studies were feasible, and the outcome of the scheme was consistent with the results of the study.

Table 2

Results of risk of bias assessment

Study	v1	v2	v3	v4	v5	v6	v7
Kovačič Tine 2011 (16)	Low	Low	Low	Low	Low	Low	Unclear
Demiralp Meral 2010 (11)	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Kurt Berna 2018 (17)	Unclear	High	Unclear	Unclear	Low	Low	Low
Pruthi Sandhya 2012 (18)	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Vuttanon Nuttamon 2019 (19)	Unclear	Unclear	Unclear	Unclear	Low	Low	Low
Yoo Hee J 2005 (20)	Unclear	Low	Unclear	Unclear	Low	Low	Unclear
Chun-Li Song 2019 (27)	Low	Unclear	Unclear	Unclear	Low	Low	Unclear
Linnan Yuan 2017 (26)	Low	Unclear	Unclear	Unclear	Low	Low	Unclear
Xu-Yan Xi 2019 (25)	High	Unclear	Unclear	Unclear	Low	Low	Unclear
Min Chen 2021 (21)	High	Unclear	Unclear	Unclear	Low	Low	Unclear
Ningrui Hou 2017 (23)	Low	Unclear	Unclear	Unclear	Low	Low	Unclear
Wei Jiao 2016 (24)	Unclear	Unclear	Unclear	Unclear	Low	Low	Unclear
Yuhua Liu 2020 (22)	Unclear	Unclear	Unclear	Unclear	Low	Low	Unclear

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v1-v7 shows random-sequence generation, allocation concealment, performance blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and other bias.

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Figure 2

Summary of risk of bias.

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Figure 3

Chart of risk of bias.

Results of the meta-analysis

Depression degree

Of the included studies, 6 (21,23-27) (comprising a total of 949 patients) reported on the effects of muscle relaxation training on the level of depression of patients. A random-effects model was adopted (I²=84.6%, P=0.000), and the combined results showed that the difference between the 2 groups was statistically significant (–9.31, 95% CI: –11.96, –6.65). Thus, muscle relaxation training for the adjuvant treatment of breast cancer patients was significantly better than conventional care in terms of reducing depression (see Figure 4A).

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Figure 4

Analysis of depression. WMD, weight mean difference; s.e. of: WMD, standard error of weighted mean difference.

A subgroup analysis was carried out according to the study types, and the results showed that the heterogeneity mainly originated from 2 quasi-RCTs, and there was a large heterogeneity between the quasi-RCTs and RCTs.

For the outcome measure of depression, we used a funnel chart to demonstrate the publication bias, and the Egger’s test and Begg’s test to analyze the funnel chart. The results of the tests (P>0.05) indicated that the possibility of publication bias was small. Additionally, the sensitivity analysis results showed that the effect size after excluding each study did not change significantly (see Figure 4B,4C).

Anxiety

Of the included studies, 6 (21,23-27) (comprising a total of 949 patients) reported on the effects of muscle relaxation training on the anxiety of patients. A fixed-effects model was adopted (I²=5.6%, P=0.381), and the combined results showed that the difference between the 2 groups was statistically significant (WMD =–8.96, 95% CI: –10.06, –7.86). Thus, muscle relaxation training adjuvant therapy for breast cancer patients was significantly better than conventional nursing in terms of reducing anxiety (see Figure 5A).

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Figure 5

Analysis of anxiety. WMD, weight mean difference; s.e. of: WMD, standard error of weighted mean difference.

For the outcome measure of anxiety, we used a funnel chart to display the publication bias, and the Egger’s test and Begg’s test to analyze the funnel chart. The results of the tests (P>0.05) indicated that the possibility of publication bias was low. Additionally, the sensitivity analysis results showed that the effect size after excluding each study did not change significantly (see Figure 5B,5C).

QoL

Of the included studies, 8 (18,20,21,23-27) (comprising a total of 1,039 patients) reported on the effects of muscle relaxation training on patients’ QoL. A random-effects model was adopted (I²=97.2%, P=0.000), and the combined results showed that the difference between the 2 groups was statistically significant (WMD =13.13, 95% CI: 7.24, 19.02). Thus, muscle relaxation training treatment was significantly better than conventional care in improving the QoL of breast cancer patients (see Figure 6A).

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Figure 6

Analysis of QoL. QoL, quality of life. WMD, weight mean difference; s.e. of: WMD, standard error of weighted mean difference.

A subgroup analysis was carried out according to the study type, and the results showed that the heterogeneity mainly originated from 2 quasi-RCTs, and there was a large heterogeneity between the quasi-RCTs and RCTs.

For the outcome measure of QoL, we used a funnel chart to display the publication bias, and used the Egger’s test and Begg’s test to analyze the funnel chart. The results of the tests (P>0.05) indicated that the possibility of publication bias was low. Additionally, a sensitivity analysis was carried out by excluding individual studies one by one. The results showed that this study (25) had a great impact on the results, which may be related to the high risk of random allocation of odd and even numbers. However, after excluding the above study, the combined analysis results showed no fundamental changes, indicating that the results of the meta-analysis were relatively stable (see Figure 6B,6C).

Discussion

We conducted a meta-analysis of RCTs and quasi-RCTs to examine the effects of muscle relaxation training on the mental health and QoL of breast cancer patients compared to conventional care. In total, 13 RCTs and quasi-RCTs, were included in the meta-analysis. The results showed that compared to conventional care, muscle relaxation training significantly reduced the level of depression and level of anxiety of breast cancer patients, and improved their QoL.

With advancements in diagnosis and treatment, the life span of breast cancer patients has been prolonged, but studies have shown that nearly 50% of breast cancer patients suffer from psychological distress during diagnosis and treatment or recovery, which seriously affect their QoL (5,28). Thus, more attention needs to be paid to patients’ QoL during and after cancer treatment. It is necessary to explore an effective way to intervene in patients’ psychological health and quality of life to improve their QoL. Thus, we used depression, anxiety, and QoL as the outcome measures in this meta-analysis to examine the effect of conventional nursing and muscle relaxation training on patients’ mental health and QoL.

The latest meta-analysis published by Ramírez-Vélez et al. (29) confirmed that exercise moderately improved the QoL of breast cancer patients, and also slightly improved different aspects, such as anxiety, body shape and appearance, depression, overall QoL, and emotional function. It also pointed out the limitations of related meta-analysis research, including the lack of evidence for some important outcome measures, and the limitation of the method of RCT. The meta-analysis of Yi et al. (30) showed that yoga may help to reduce fatigue, depression and anxiety, improve sleep disorders, and improve the QoL of breast cancer patients receiving short-term chemotherapy. However, due to the inconsistent control group in the study, it is not yet clear whether yoga has a significant advantage over other treatments. Notably, our research was based on RCTs and quasi-RCTs, and we found that muscle relaxation training significantly improved the level of depression and the level of anxiety of patients and improved their QoL compared to conventional care, and thus improved patients’ management of bad emotions and their QoL.

However, this study still had some limitations. First, while we conducted a comprehensive search of mainstream databases, there are still a few RCTs that could have been included in this meta-analysis. Second, the collection of characteristic factors was limited, and the history of abortion, history of contraception, history of benign breast diseases, and other clinical factors and basic demographic characteristics were not examined.

In summary, this study has important clinical significance. It emphasizes the importance of a more systematic screening of breast cancer patients’ anxiety, depression, and QoL. It also emphasizes the necessity of using muscle relaxation training in breast cancer care to improve patients’ mental health and QoL. Our findings can be used by oncologists, cancer nurses, and physical therapists, and provide a reference for future cancer rehabilitation management.

Conclusions

Based on the limited evidence, compared to conventional care, muscle relaxation training significantly reduces the level of depression and level of anxiety of breast cancer patients and improves their QoL. This meta-analysis was limited by the number and the quality of the included studies. The above conclusions need to be verified by larger-scale and multi-center investigations, using more accurate and high-quality studies.

Acknowledgments

Notes

Ethical Statement: The authors are accountable for all aspects of the work, including ensuring that any questions related to the accuracy or integrity of any part of the work have been appropriately investigated and resolved.

Footnotes

References