title: Weight Loss and Mortality in Overweight and Obese Cancer Survivors: A Systematic Review.
abstract: BACKGROUND
  Excess adiposity is a risk factor for poorer cancer survival, but there is uncertainty over whether losing weight reduces the risk. We conducted a critical review of the literature examining weight loss and mortality in overweight or obese cancer survivors.
  
  
  METHODS
  We systematically searched PubMed and EMBASE for articles reporting associations between weight loss and mortality (cancer-specific or all-cause) in overweight/obese patients with obesity-related cancers. Where available, data from the same studies on non-overweight patients were compared.
  
  
  RESULTS
  Five articles describing observational studies in breast cancer survivors were included. Four studies reported a positive association between weight loss and mortality in overweight/obese survivors, and the remaining study observed no significant association. Results were similar for non-overweight survivors. Quality assessment indicated high risk of bias across studies.
  
  
  CONCLUSIONS
  There is currently a lack of observational evidence that weight loss improves survival for overweight and obese cancer survivors. However, the potential for bias in these studies is considerable and the results likely reflect the consequences of disease-related rather than intentional weight loss. There is a need for stronger study designs, incorporating measures of intentionality of weight loss, and extended to other cancers.
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, United Kingdom.
authors.forename: Sarah E
authors.identifier: http://orcid.org/0000-0001-5658-6168
authors.initials: SE
authors.lastname: Jackson
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, United Kingdom.
authors.forename: Malgorzata
authors.initials: M
authors.lastname: Heinrich
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, United Kingdom.
authors.forename: Rebecca J
authors.initials: RJ
authors.lastname: Beeken
authors.affiliation: Health Behaviour Research Centre, Department of Epidemiology and Public Health, University College London, London, WC1E 6BT, United Kingdom.
authors.forename: Jane
authors.initials: J
authors.lastname: Wardle
mesh_terms: D001943:Breast Neoplasms / Q000150:complications* / Q000401:mortality / Q000503:physiopathology*; D005260:Female; D006801:Humans; D008875:Middle Aged; D009765:Obesity / Q000150:complications* / Q000503:physiopathology*; D050177:Overweight / Q000150:complications* / Q000503:physiopathology*; D015431:Weight Loss / Q000502:physiology