title: Low skeletal muscle radiation attenuation and visceral adiposity are associated with overall survival and surgical site infections in patients with pancreatic cancer.
abstract: BACKGROUND
  Cancer cachexia and skeletal muscle wasting are related to poor survival. In this study, quantitative body composition measurements using computed tomography (CT) were investigated in relation to survival, post-operative complications, and surgical site infections in surgical patients with cancer of the head of the pancreas.
  
  
  METHODS
  A prospective cohort of 199 patients with cancer of the head of the pancreas was analysed by CT imaging at the L3 level to determine (i) muscle radiation attenuation (average Hounsfield units of total L3 skeletal muscle); (ii) visceral adipose tissue area; (iii) subcutaneous adipose tissue area; (iv) intermuscular adipose tissue area; and (v) skeletal muscle area. Sex-specific cut-offs were determined at the lower tertile for muscle radiation attenuation and skeletal muscle area and the higher tertile for adipose tissues. These variables of body composition were related to overall survival, severe post-operative complications (Dindo-Clavien ≥ 3), and surgical site infections (wounds inspected daily by an independent trial nurse) using Cox-regression analysis and multivariable logistic regression analysis, respectively.
  
  
  RESULTS
  Low muscle radiation attenuation was associated with shorter survival in comparison with moderate and high muscle radiation attenuation [median survival 10.8 (95% CI: 8.8-12.8) vs. 17.4 (95% CI: 14.7-20.1), and 18.5 (95% CI: 9.2-27.8) months, respectively; P < 0.008]. Patient subgroups with high muscle radiation attenuation combined with either low visceral adipose tissue or age <70 years had longer survival than other subgroups (P = 0.011 and P = 0.001, respectively). Muscle radiation attenuation was inversely correlated with intermuscular adipose tissue (rp= -0.697, P < 0.001). High visceral adipose tissue was associated with an increased surgical site infection rate, OR: 2.4 (95% CI: 1.1-5.3; P = 0.027).
  
  
  CONCLUSIONS
  Low muscle radiation attenuation was associated with reduced survival, and high visceral adiposity was associated with an increase in surgical site infections. The strong correlation between muscle radiation attenuation and intermuscular adipose tissue suggests the presence of ectopic fat in muscle, warranting further investigation. CT image analysis could be implemented in pre-operative risk assessment to assist in treatment decision-making.
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.|NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
authors.forename: David P J
authors.initials: DP
authors.lastname: van Dijk
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Maikel J A M
authors.initials: MJ
authors.lastname: Bakens
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Mariëlle M E
authors.initials: MM
authors.lastname: Coolsen
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.|NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.
authors.forename: Sander S
authors.initials: SS
authors.lastname: Rensen
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.
authors.forename: Ronald M
authors.initials: RM
authors.lastname: van Dam
authors.affiliation: Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.|GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Martijn J L
authors.initials: MJ
authors.lastname: Bours
authors.affiliation: Department of Epidemiology, Maastricht University, Maastricht, The Netherlands.|GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Matty P
authors.initials: MP
authors.lastname: Weijenberg
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.|NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.|GROW School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Cornelis H C
authors.initials: CH
authors.lastname: Dejong
authors.affiliation: Department of Surgery, Maastricht University Medical Centre, Maastricht, The Netherlands.|NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University, Maastricht, The Netherlands.|Institute for Liver and Digestive Health, University College London, London, UK.
authors.forename: Steven W M
authors.initials: SW
authors.lastname: Olde Damink
mesh_terms: D000368:Aged; D001823:Body Composition; D005260:Female; D006801:Humans; D050152:Intra-Abdominal Fat / Q000000981:diagnostic imaging*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000000981:diagnostic imaging*; D010190:Pancreatic Neoplasms / Q000000981:diagnostic imaging* / Q000601:surgery*; D050151:Subcutaneous Fat / Q000000981:diagnostic imaging; D013530:Surgical Wound Infection / Q000209:etiology*
keywords: Body composition; Computed tomography; Pancreatic cancer; Radiation attenuation; Surgical site infection; Visceral adipose tissue