title: Neuropeptide Y, leptin, and cholecystokinin 8 in patients with advanced cancer and anorexia: a North Central Cancer Treatment Group exploratory investigation.
abstract: BACKGROUND
  Anorexia is a noxious symptom, and over half of patients with advanced cancer experience it. Neuropeptide Y (NPY), leptin, and cholecystokinin 8 (CCK8) have been implicated.
  
  
  METHODS
  This exploratory study 1) compared circulating concentrations of NPY and leptin between anorectic cancer patients and historic controls and 2) explored whether NPY, leptin, or CCK8 may serve as correlates of anorexia severity. Cancer patients met predefined eligibility criteria: 1) weight loss > or = 2.3 kg over the preceding 2 months and/or a physician-estimated caloric intake of < 20 calories per kilogram of body weight per day and 2) patient acknowledgment that appetite or weight loss was an ongoing problem.
  
  
  RESULTS
  Seventy-three cancer patients were studied, and > 90% reported a > or = 50% decline in appetite from baseline in the preceding 2 months. NPY levels were lower than control values: mean +/- standard deviation, 466 pg/mL +/- 161 pg/mL versus 560 pg/mL +/- 151 pg/mL, respectively (P = 0.004). Because a few (but not all) earlier studies suggested an age-related decline in NPY levels, a subgroup analysis was performed and found no age-adjusted difference in NPY levels between groups. Similarly, leptin concentrations were not different between groups. Significant correlations were not observed between anorexia severity and NPY, leptin, or CCK8 levels.
  
  
  CONCLUSIONS
  There were no differences in leptin and CCK8 levels between anorectic cancer patients and historic controls. Circulating concentrations of NPY, leptin, and CCK8 did not correlate with anorexia severity. However, the current results suggest a need for further examination of NPY in cancer-associated anorexia.
authors.affiliation: Mayo Clinic and Mayo Foundation, 200 First Street SW, Rochester, MN 55905, USA. jatoi.aminah@mayo.edu
authors.forename: A
authors.initials: A
authors.lastname: Jatoi
authors.forename: C L
authors.initials: CL
authors.lastname: Loprinzi
authors.forename: J A
authors.initials: JA
authors.lastname: Sloan
authors.forename: G G
authors.initials: GG
authors.lastname: Klee
authors.forename: H E
authors.initials: HE
authors.lastname: Windschitl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000855:Anorexia / Q000209:etiology / Q000378:metabolism*; D002766:Cholecystokinin / Q000378:metabolism*; D005260:Female; D006801:Humans; D020738:Leptin / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009369:Neoplasms / Q000150:complications / Q000378:metabolism*; D009478:Neuropeptide Y / Q000378:metabolism*; D010446:Peptide Fragments / Q000378:metabolism*
chemical_list: D020738:Leptin; D009478:Neuropeptide Y; D010446:Peptide Fragments; C410885:cholecystokinin 8; D002766:Cholecystokinin