The efficacy of mindfulness-based stress reduction vs. standard or usual care in patients with breast cancer: a systematic review and meta-analysis of randomized controlled trials.

BACKGROUND: Mindfulness-based stress reduction (MBSR) has become an alternative intervention for cancer patients, but its impact on depression and quality of life (QOL) of breast cancer patients remains controversial. The aim of this study was to evaluate the effects of MBSR vs. standard or usual care to relieve psychological stress in patients with breast cancer.

METHODS: According to the PICOS principles, databases [PubMed, Cochrane Database, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), China Scientific Journal Database (VIP), and Wanfang Database] were searched for randomized controlled trials (RCTs) on the evaluation of MBSR vs. standard or usual care for patients with breast cancer, the outcome variables included depression, stress, anxiety, fatigue, sleep and QOL. Review Manager 5.4 was used to evaluate the effects of the results among selected articles. Forest plots and funnel plots were also performed. The risk of bias was assessed using the Cochrane Risk of Bias Tool.

RESULTS: The final analysis included 14 studies with a total of 2,224 patients (1,138 in the MBSR group and 1,086 in the control group). The overall results of risk of bias assessment showed that the reporting bias among articles was high, and other bias was relatively moderate. Funnel plots and Egger's tests showed that there was no significant publication bias. Compared with standard or usual care, MBSR effectively relieved the psychological stress [mean difference (MD), -1.72; 95% confidence interval (CI): (-2.53, -0.92); P<0.0001] and anxiety [standardized mean difference (SMD), -1.36; 95% CI: (-2.13, -0.60); P=0.0005] of breast cancer patients, and improved depression [SMD, -0.62; 95% CI: (-1.20, -0.03); P=0.04] and sleep status [MD, -0.42; 95% CI: (-0.73, -0.10), P=0.009]. However, it had no significant effect on fatigue [SMD, -0.97; 95% CI: (-2.24, 0.31); P=0.14] or QOL [MD, 1.95; 95% CI: (-3.15, 7.05); P=0.45].

CONCLUSIONS: MBSR was better than standard or usual care for relieving psychological stress, anxiety, depression, and sleep in patients with breast cancer. Considering the limitations of this article, such as high risk of bias and high heterogeneity of included studies, the interpretation of this conclusion should be cautious.