title: Cancer cachexia: a systematic literature review of items and domains associated with involuntary weight loss in cancer.
abstract: BACKGROUND
  The concept of cancer-related anorexia/cachexia is evolving as its mechanisms are better understood. To support consensus processes towards an updated definition and classification system, we systematically reviewed the literature for items and domains associated with involuntary weight loss in cancer.
  
  
  METHODS
  Two search strings (cachexia, cancer) explored five databases from 1976 to 2007. Citations, abstracts and papers were included if they were original work, in English/German language, and explored an item to distinguish advanced cancer patients with variable degrees of involuntary weight loss. The items were grouped into the 5 domains proposed by formal expert meetings.
  
  
  RESULTS
  Of 14,344 citations, 1275 abstracts and 585 papers reviewed, 71 papers were included (6325 patients; 40-50% gastrointestinal, 10-20% lung cancer). No single domain or item could consistently distinguish cancer patients with or without weight loss or having various degrees of weight loss. Anorexia and decreased nutritional intake were unexpectedly weakly related with weight loss. Explanations for this could be the imprecise measurement methods for nutritional intake, symptom interactions, and the importance of systemic inflammation as a catabolic drive. Data on muscle mass and strength is scarce and the impact of cachexia on physical and psychosocial function has not been widely assessed.
  
  
  CONCLUSIONS
  Current data support a modular concept of cancer cachexia with a variable combination of reduced nutritional intake and catabolic/hyper-metabolic changes. The heterogeneity in the literature revealed by this review underlines the importance of an agreed definition and classification of cancer cachexia.
authors.affiliation: Oncological Palliative Medicine, Division of Oncology/Hematology, Department of Internal Medicine and Palliative Care Center, Cantonal Hospital, St. Gallen, Switzerland. david.blum@kssg.ch
authors.forename: David
authors.initials: D
authors.lastname: Blum
authors.forename: Aurelius
authors.initials: A
authors.lastname: Omlin
authors.forename: Vickie E
authors.initials: VE
authors.lastname: Baracos
authors.forename: Tora S
authors.initials: TS
authors.lastname: Solheim
authors.forename: Benjamin H L
authors.initials: BH
authors.lastname: Tan
authors.forename: Patrick
authors.initials: P
authors.lastname: Stone
authors.forename: Stein
authors.initials: S
authors.lastname: Kaasa
authors.forename: Ken
authors.initials: K
authors.lastname: Fearon
authors.forename: Florian
authors.initials: F
authors.lastname: Strasser
mesh_terms: D000855:Anorexia / Q000150:complications; D002100:Cachexia / Q000209:etiology*; D002149:Energy Intake; D004734:Energy Metabolism; D006801:Humans; D009369:Neoplasms / Q000150:complications*