title: The assessment and impact of sarcopenia in lung cancer: a systematic literature review.
abstract: OBJECTIVE
  There is growing awareness of the relationship between sarcopenia (loss of muscle mass and function), and outcomes in cancer, making it a potential target for future therapies. In order to inform future research and practice, we undertook a systematic review of factors associated with loss of muscle mass, and the relationship between muscle function and muscle mass in lung cancer, a common condition associated with poor outcomes.
  
  
  METHODS
  We conducted a computerised systematic literature search on five databases. Studies were included if they explored muscle mass as an outcome measure in patients with lung cancer, and were published in English.
  
  
  METHODS
  Secondary care.
  
  
  METHODS
  Patients with lung cancer.
  
  
  METHODS
  Factors associated with loss of muscle mass and muscle function, or sarcopenia, and the clinical impact thereof in patients with lung cancer.
  
  
  RESULTS
  We reviewed 5726 citations, and 35 articles were selected for analysis. Sarcopenia, as defined by reduced muscle mass alone, was found to be very prevalent in patients with lung cancer, regardless of body mass index, and where present was associated with poorer functional status and overall survival. There were diverse studies exploring molecular and metabolic factors in the development of loss of muscle mass; however, the precise mechanisms that contribute to sarcopenia and cachexia remain uncertain. The effect of nutritional supplements and ATP infusions on muscle mass showed conflicting results. There are very limited data on the correlation between degree of sarcopenia and muscle function, which has a non-linear relationship in older non-cancer populations.
  
  
  CONCLUSIONS
  Loss of muscle mass is a significant contributor to morbidity in patients with lung cancer. Loss of muscle mass and function may predate clinically overt cachexia, underlining the importance of evaluating sarcopenia, rather than weight loss alone. Understanding this relationship and its associated factors will provide opportunities for focused intervention to improve clinical outcomes.
authors.affiliation: Cardiff University, Cardiff, UK.
authors.forename: Jemima
authors.initials: J
authors.lastname: Collins
authors.forename: Simon
authors.initials: S
authors.lastname: Noble
authors.forename: John
authors.initials: J
authors.lastname: Chester
authors.forename: Bernadette
authors.initials: B
authors.lastname: Coles
authors.forename: Anthony
authors.initials: A
authors.lastname: Byrne
mesh_terms: D002100:Cachexia / Q000209:etiology*; D006801:Humans; D008175:Lung Neoplasms / Q000150:complications*; D055948:Sarcopenia / Q000150:complications*