title: Risk factors, prevalence, and course of severe fatigue after breast cancer treatment: a meta-analysis involving 12 327 breast cancer survivors.
abstract: This meta-analysis aimed to (i) examine demographic, disease-related, and treatment-related risk factors, (ii) estimate the prevalence, and (iii) describe the course of severe fatigue following breast cancer (BC) treatment.
  
  
  
  PubMed, PsycINFO, Cochrane, CINAHL, and Web of Science were systematically searched from inception up to 23 November 2015. Risk factors and prevalence rates were analyzed with inverse variance random-effects analyses. Heterogeneity was studied with sensitivity analyses.
  
  
  
  Twenty-seven studies were included (N = 12 327). Breast cancer survivors (BCS) with a partner were at lower risk for severe fatigue than survivors without a partner [risk ratio (RR) 0.96, 95% confidence interval (CI) 0.93-0.98]. Survivors with stage II or III cancer, and survivors treated with chemotherapy were at higher risk for severe fatigue than survivors with stage 0 or I cancer and without chemotherapy (RR respectively 1.18, 95% CI 1.08-1.28; 1.12, 95% CI 1.06-1.19). Survivors treated with surgery, radiotherapy, and chemotherapy, and survivors with this combination plus hormone therapy were at higher risk than survivors with other treatment combinations (RR respectively 1.18, 95% CI 1.05-1.33; 1.38, 95% CI 1.15-1.66). Survivors treated with surgery and surgery plus radiotherapy were at lower risk than survivors with additional treatments (RR respectively 0.83, 95% CI 0.70-0.98; 0.87, 95% CI 0.78-0.96). Hormone and targeted therapy were no significant risk factors. The pooled prevalence of severe fatigue was 26.9% (95% CI 23.2-31.0), but this should be interpreted with caution because of high heterogeneity. A relatively large decrease in the prevalence of severe fatigue seemed to occur in the first half year after treatment completion.
  
  
  
  Approximately one in four BCS suffer from severe fatigue. Risk factors of severe fatigue were higher disease stages, chemotherapy and receiving the combination of surgery, radiotherapy, and chemotherapy, both with and without hormone therapy. Having a partner, receiving only surgery, and surgery plus radiotherapy decreased the risk.
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center, Nijmegen. Electronic address: harriet.abrahams@radboudumc.nl.
authors.forename: H J G
authors.initials: HJG
authors.lastname: Abrahams
authors.affiliation: Department of Medical Psychology, Academic Medical Center, University of Amsterdam, Amsterdam.
authors.forename: M F M
authors.initials: MFM
authors.lastname: Gielissen
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center, Nijmegen.
authors.forename: I C
authors.initials: IC
authors.lastname: Schmits
authors.affiliation: Department of Medical Oncology.
authors.forename: C A H H V M
authors.initials: CAHHVM
authors.lastname: Verhagen
authors.affiliation: Radboud Institute for Health Sciences, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: M M
authors.initials: MM
authors.lastname: Rovers
authors.affiliation: Expert Center for Chronic Fatigue, Radboud University Medical Center, Nijmegen; Department of Medical Psychology, Academic Medical Center, University of Amsterdam, Amsterdam.
authors.forename: H
authors.initials: H
authors.lastname: Knoop
mesh_terms: D001943:Breast Neoplasms / Q000188:drug therapy* / Q000453:epidemiology* / Q000532:radiotherapy / Q000601:surgery; D000073116:Cancer Survivors; D005221:Fatigue / Q000139:chemically induced / Q000453:epidemiology* / Q000473:pathology; D005260:Female; D006801:Humans; D009367:Neoplasm Staging; D012307:Risk Factors; D016896:Treatment Outcome
keywords: breast cancer; course; fatigue; meta-analysis; prevalence; risk factors