title: Impact of the preoperative quantity and quality of skeletal muscle on outcomes after resection of extrahepatic biliary malignancies.
abstract: BACKGROUND
  Skeletal muscle depletion, referred to as sarcopenia, predicts mortality after major surgery. This study investigated the impact of preoperative skeletal muscle quantity and quality on outcomes in patients undergoing resection of extrahepatic biliary cancer.
  
  
  METHODS
  We performed a retrospective analysis of 207 patients undergoing resection for biliary cancer between 2004 and 2013. The quantity and quality of skeletal muscle, indicated by the psoas muscle mass index (PMI) and intramuscular adipose tissue content (IMAC), were measured on preoperative images of computed tomography. Overall survival (OS) and recurrence-free survival (RFS) rates were compared by PMI and IMAC, and prognostic factors after operation were assessed.
  
  
  RESULTS
  The OS and RFS rates were less in patients with low PMI (low muscle quantity) than in those with normal PMI (P < .001 and P < .001; 5-year OS, 15.7 vs 53.5%). The OS and RFS rates were also less in patients with high IMAC (low muscle quality) than in those with normal IMAC (P < .001 and P < .001; 5-year OS, 23.8 vs 55.9%). Low PMI and high IMAC were independent factors predictive of poor OS (hazard ratio [HR], 2.921 [95% CI, 1.920-4.470; P < .001] and HR, 1.725 [95% CI, 1.159-2.590; P = .007]) and RFS (HR, 2.141 [95% CI, 1.464-3.129, P < .001] and HR, 1.492 [95% CI, 1.032-2.166, P = .034]).
  
  
  CONCLUSIONS
  Preoperative sarcopenia, indicating a low quantity and quality of skeletal muscle, is related closely to mortality after resection of biliary cancer.
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shinya
authors.initials: S
authors.lastname: Okumura
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan. Electronic address: kaido@kuhp.kyoto-u.ac.jp.
authors.forename: Toshimi
authors.initials: T
authors.lastname: Kaido
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Yuhei
authors.initials: Y
authors.lastname: Hamaguchi
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Yasuhiro
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Kobayashi
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Taku
authors.initials: T
authors.lastname: Iida
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shintaro
authors.initials: S
authors.lastname: Yagi
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Taura
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Etsuro
authors.initials: E
authors.lastname: Hatano
authors.affiliation: Division of Hepato-Biliary-Pancreatic and Transplant Surgery, Department of Surgery, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
mesh_terms: D000368:Aged; D017734:Bile Ducts, Extrahepatic / Q000473:pathology / Q000601:surgery*; D001661:Biliary Tract Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D015331:Cohort Studies; D018572:Disease-Free Survival; D005260:Female; D005500:Follow-Up Studies; D006498:Hepatectomy / Q000009:adverse effects* / Q000379:methods / Q000401:mortality; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D061330:Multidetector Computed Tomography / Q000379:methods; D015999:Multivariate Analysis; D009133:Muscular Atrophy / Q000000981:diagnostic imaging / Q000209:etiology*; D011183:Postoperative Complications / Q000401:mortality / Q000503:physiopathology; D011237:Predictive Value of Tests; D011300:Preoperative Care; D016016:Proportional Hazards Models; D016658:Psoas Muscles / Q000000981:diagnostic imaging / Q000473:pathology*; D012189:Retrospective Studies; D018570:Risk Assessment; D055948:Sarcopenia / Q000000981:diagnostic imaging / Q000209:etiology; D015996:Survival Rate