Effects of physical exercise after treatment of early breast cancer: systematic review and meta-analysis
Randomized clinical trials are inconclusive regarding the role of physical exercise in anthropometric measurements, quality of life, and survival in breast cancer patients. Our aim was to conduct a systematic review and meta-analysis to assess the effects of physical exercise on these outcomes in women who went through curative treatment of early-stage breast cancer.
Pubmed, Embase, Cochrane Library were searched for randomized clinical trial comparing physical exercise (counseling or structured programs with supervised/individualized exercise sessions) with usual care in women that went through for breast cancer treatment. Primary outcomes were overall survival and disease-free survival, while secondary outcomes were weight loss, body mass index, waist–hip ratio, percentage of body fat, and quality of life.
We found 60 randomized clinical trials, only one of them showed mortality data; the HR for mortality was 0.45 (95% CI 0.21–0.97) for the intervention group when compared to the control group. Physical exercise was associated with weight reduction (− 1.36 kg, 95% CI − 2.51 to − 0.21, p = 0.02), lower body mass index (− 0.89 kg/m2, 95% CI − 1.50 to − 0.28, p < 0.01), and lower percentage of body fat (− 1.60 percentage points, 95% CI − 2.31 to − 0.88, p < 0.01). There was an increase in the quality of life (standardized mean difference of 0.45, 95% CI 0.20–0.69, p < 0.01).
The articles found had heterogeneous types of intervention, but they showed significant effects on anthropometric measures and quality of life. Among them, only one study had mortality as outcome and it showed physical exercise as a protective intervention. Despite these findings, publication bias and poor methodological quality were presented. Physical exercise should be advised for breast cancer survivors since it has no adverse effects and can improve anthropometrics measures and quality of life. PROSPERO registry: CRD42014008743.
KeywordsBreast cancer Meta-analysis Physical exercise Quality of life
Compliance with ethical standards
Conflict of interest
The authors declare no conflicts of interest to carry out this work.
- 11.Higgins J, Green S (2011) Cochrane handbook for systematic reviews of interventions. Version 5.1.0, In: The Cochrane CollaborationGoogle Scholar
- 13.Harrigan M, Cartmel B, Loftfield E et al (2016) Randomized trial comparing telephone versus in-person weight loss counseling on body composition and circulating biomarkers in women treated for breast cancer: the lifestyle, exercise, and nutrition (LEAN) study. J Clin Oncol 34:669–676CrossRefPubMedGoogle Scholar
- 23.Hayes SC, Steele M, Spence R et al (2017) Can exercise influence survival following breast cancer: Results from a randomised, controlled trial. J Clin Oncol 35(Suppl 15):10067Google Scholar
- 36.Duijts S, Beurden M, Oldenburg H et al (2012) Efficacy of cognitive behavioral therapy and physical exercise in alleviating treatment-induced menopausal symptoms in patients with breast cancer: results of a randomized, controlled, multicenter trial. J Clin Oncol 30:4124–4133CrossRefPubMedGoogle Scholar
- 37.Fairey AS, Courneya KS, Field CJ et al (2003) Effects of exercise training on fasting insulin, insulin resistance, insulin-like growth factors, and insulin-like growth factor binding proteins in postmenopausal breast cancer survivors: a randomized controlled trial. Cancer Epidemiol Biomark Prev 12:721–727Google Scholar
- 39.Galiano-Castillo N, Cantarero-Villanueva I, Fernández-Lao C et al (2016) Telehealth system: a randomized controlled trial evaluating the impact of an internet-based exercise intervention on quality of life, pain, muscle strength, and fatigue in breast cancer survivors. Cancer 122:3166–3174CrossRefPubMedGoogle Scholar
- 43.Greenlee H, Awad D, Crew K et al (2013) Influence of a clinic-based survivorship intervention on dietary change and lifestyle recommendations among Hispanic and non-Hispanic women following adjuvant therapy for breast cancer. Cancer research. https://doi.org/10.1158/0008-5472.SABCS13-P3-08-12 Google Scholar
- 51.Kwiatkowski F, Mouret-Reynier M, Duclos M et al (2013) Long term improved quality of life by a 2-week group physical and educational intervention shortly after breast cancer chemotherapy completion. Results of the ‘Programme of Accompanying women after breast Cancer treatment completion in Thermal resorts’ (PACThe) randomised clinical trial of 251 patients. Eur J Cancer (Oxford, England: 1990) 49:1530–1538CrossRefGoogle Scholar
- 71.Sturgeon KM, Dean LT, Heroux M et al (2016) Commercially available lifestyle modification program: randomized controlled trial addressing heart and bone health in BRCA1/2+ breast cancer survivors after risk-reducing salpingo-oophorectomy. J Cancer Surviv 11:246–255CrossRefPubMedPubMedCentralGoogle Scholar
- 74.Tirado-Gomez M, Palacios C, Ortiz A, et al (2015) Serum adipokines and inflammatory markers in Hispanic breast cancer survivors. Cancer Epidemiology Biomarkers and Prevention. In: Conference: 7th AACR Conference on the Science of Health Disparities in Racial/Ethnic Minorities and the Medically Underserved San Antonio, TX United States. Conference Start: 20141109 Conference End: 20141112. Conference Publication: (var.pagings), vol 24, 2015Google Scholar