Effect of Tai Chi Chuan in Breast Cancer Patients: A Systematic Review and Meta-Analysis

Background: Tai Chi Chuan(TCC), as a mind-body exercise, may have a positive effect on physical function and psychological well-being in breast cancer patients. The latest systematic review and meta-analysis of TCC for breast cancer had been done four years ago and some new studies about this were published. We remade a systematic review and meta-analysis to assess the effect of TCC in breast cancer patients. <br><br>Methods: In this systematic review and meta-analysis, we searched MEDLINE (via PubMed), EMBASE (via embase.com), CENTRAL, CNKI, VIP, Wanfang, Chaoxing, CiNii, J-SSTAGE, DBpia and ThaiJO with no language restrictions from inception to December 31, 2018, for randomised clinical trials comparing TCC with non-exercised therapy in breast cancer patients. Studies was excluded for interest diseases were not only breast cancer and experimental intervention was TCC combining other exercise. Data extracted independently by two investigators and any disagreements were resolved by discussion and consensus. The primary outcome was quality of life (QOL) in patients with breast cancer and data pooled by a random-effects model. Subgroup analyses were done to estimate the effect of different duration of TCC for breast cancer patients. This study was registered with PROSPERO, number CRD 4201810326. <br><br>Findings: Fourteen studies involving a total of 841 breast cancer participants were included in this review. Compared with non-exercised therapy, TCC had a significant effect on QOL in breast cancer patients (SMD=0·37, 95% CI 0·15 to 0·59, p=0·001, I2=0%), and subgroup analysis found that TCC showed beneficial effect in 12 weeks and 25 weeks (12 weeks: SMD=0·40, 95% CI 0·19 to 0·62, p=0·0003, I2=0%; 25 weeks: SMD=0·38,95% CI 0·15 to 0·62, p=0·002, I2=0%), not in 3 weeks and 6 weeks (3 weeks: SMD=0·23, 95% CI -0·01 to 0·47, p=0·06, I2=0%; 6 weeks: SMD=0·04, 95% CI -0·52 to 0·60, p=0·89, I2=0%). Meta-analyses of secondary outcomes showed that 3 weeks TCC increased shoulder function (SMD=1·08, 95% CI 0·28 to 1·87, p=0·008, I2=91%), 12 weeks TCC improved pain (SMD=0·30, 95% CI 0·08 to 0·51, p=0·007, I2=0%), shoulder function (SMD=1·34, 95% CI 0·43 to 2·25, p=0·004, I2=92%), strength of arm (SMD=0·44, 95% CI 0·20 to 0·68, p=0·0004, I2=16%), and anxiety (MD=-4·90, 95% CI -7·83 to -1·98, p=0·001, I2=84) and TCC decreased fatigue (SMD=- 0·91, 95% CI -1·30 to -0·53, p&lt;0·00001, I2=0%) in breast cancer patients compared with the control group.<br><br>Interpretation: TCC appears to be effective on some physical and psychological symptoms and improves QOL in patients with breast cancer. Additional randomised controlled trials with rigorous methodology and low risk of bias are needed to provide more reliable evidence.<br><br>Funding Statement: This work has been supported by Sichuan Science and Technology Program (2019YFH0108, 2018SZ0257) and Innovative Research Team in University of Sichuan Province (16TD0015).<br><br>Declaration of Interests: The authors declare that there is no conflict of interests relevant to the report of this paper.<br><br>Ethics Approval Statement: The report of this systematic review and meta-analysis is followed by the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA).