title: The relationship between muscle protein content and CT-derived muscle radio-density in patients with upper GI cancer.
abstract: Cancer cachexia is a multifactorial syndrome characterized by skeletal muscle loss. Cross-sectional analysis of CT scans is a recognized research method for assessing skeletal muscle volume. However, little is known about the relationship between CT-derived estimates of muscle radio-density (SMD) and muscle protein content. We assessed the relationship between CT-derived body composition variables and the protein content of muscle biopsies from cancer patients.
  
  
  
  Rectus abdominis biopsies from cancer patients (n = 32) were analysed for protein content and correlated with phenotypic data gathered using CT body composition software.
  
  
  
  Skeletal muscle protein content varied widely between patients (median μg/mg wet weight = 89.3, range 70-141). There was a weak positive correlation between muscle protein content and SMD (r = 0.406, p = 0.021), and a weak positive correlation between protein content and percentage weight change (r = 0.416, p = 0.018).
  
  
  
  The protein content of skeletal muscle varies widely in cancer patients and cannot be accurately predicted by CT-derived muscle radio-density.
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK. Electronic address: mramage@exseed.ed.ac.uk.
authors.forename: Michael I
authors.initials: MI
authors.lastname: Ramage
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK. Electronic address: neiljohns@doctors.org.uk.
authors.forename: Neil
authors.initials: N
authors.lastname: Johns
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK. Electronic address: chris.deans@nhslothian.scot.nhs.uk.
authors.forename: Christopher D A
authors.initials: CDA
authors.lastname: Deans
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK. Electronic address: j.a.ross@ed.ac.uk.
authors.forename: James A
authors.initials: JA
authors.lastname: Ross
authors.affiliation: Stable Isotope Biochemistry Laboratory, Scottish Universities Environmental Research Centre, Rankine Avenue, Scottish Enterprise Technology Park, East Kilbride, Glasgow, G75 0QF, Scotland, UK. Electronic address: tom.preston@glasgow.ac.uk.
authors.forename: Thomas
authors.initials: T
authors.lastname: Preston
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK. Electronic address: richard.skipworth@nhslothian.scot.nhs.uk.
authors.forename: Richard J E
authors.initials: RJE
authors.lastname: Skipworth
authors.affiliation: Musculoskeletal Diseases Area, Muscle Group, Novartis Pharma AG, Novartis Campus, WSJ-152.2.72.04, CH-4056, Basel, Switzerland. Electronic address: carsten.jacobi@novartis.com.
authors.forename: Carsten
authors.initials: C
authors.lastname: Jacobi
authors.affiliation: Department of Clinical Surgery, Royal Infirmary of Edinburgh, 51 Little France Crescent, Edinburgh, EH16 4SA, Scotland, UK.
authors.forename: Kenneth C H
authors.initials: KCH
authors.lastname: Fearon
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D001823:Body Composition; D002100:Cachexia / Q000150:complications* / Q000378:metabolism; D003430:Cross-Sectional Studies; D005260:Female; D005770:Gastrointestinal Neoplasms / Q000150:complications* / Q000378:metabolism; D006801:Humans; D008297:Male; D008875:Middle Aged; D009124:Muscle Proteins / Q000378:metabolism*; D017568:Rectus Abdominis / Q000000981:diagnostic imaging* / Q000378:metabolism / Q000473:pathology; D015203:Reproducibility of Results; D014057:Tomography, X-Ray Computed / Q000379:methods*
chemical_list: D009124:Muscle Proteins
keywords: Body composition; Cachexia; Cancer; Imaging analysis; Protein content; Skeletal muscle