title: Optimal cut-off value for the number of colorectal liver metastases: a project study for hepatic surgery of the Japanese Society of Hepato-Biliary-Pancreatic Surgery.
abstract: BACKGROUND
  The optimal cut-off value of the number of colorectal liver metastases (CRLM) to predict prognosis after hepatic resection remains unclear. This study was conducted to determine a suitable cut-off value.
  
  
  METHODS
  A total of 727 hepatectomized patients with CRLM were evaluated. We proposed the following optimal cut-off values: first, a small P-value for the log-rank test with no overlapping of the 95% confidence interval (CI) for median survival time using the Kaplan-Meier method and the hazard ratio (HR) using the Cox proportional hazards model and, second, the maximum HR value for accurate separation.
  
  
  RESULTS
  For disease-free survival analysis, of the three group separations, A2 (1, 2-4, and ≥5) showed a small P-value and the largest HR, whereas two group separations, B2, B3 and B4 showed similarly small P-values, but B4 (1-4, ≥5) indicated the largest HR. Regarding the overall survival analysis, of the three group separations, A2 showed the smallest P-value, whereas the two group separations, B4 showed similarly small P-values, with the largest HR.
  
  
  CONCLUSIONS
  Tumor number separation in patients with CRLM after hepatic resection should be performed using the A2 (1, 2-4, and ≥5) or B4 (1-4 and ≥5) classifications.
authors.affiliation: Department of Gastroenterological Surgery, Graduate School of Life Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Toru
authors.initials: T
authors.lastname: Beppu
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Sakamoto
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Hasegawa
authors.forename: Goro
authors.initials: G
authors.lastname: Honda
authors.forename: Kuniya
authors.initials: K
authors.lastname: Tanaka
authors.forename: Yoshihito
authors.initials: Y
authors.lastname: Kotera
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nitta
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Yoshidome
authors.forename: Etsuro
authors.initials: E
authors.lastname: Hatano
authors.forename: Masaki
authors.initials: M
authors.lastname: Ueno
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takamura
authors.forename: Hideo
authors.initials: H
authors.lastname: Baba
authors.forename: Tomoo
authors.initials: T
authors.lastname: Kosuge
authors.forename: Norihiro
authors.initials: N
authors.lastname: Kokudo
authors.forename: Keiichi
authors.initials: K
authors.lastname: Takahashi
authors.forename: Itaru
authors.initials: I
authors.lastname: Endo
authors.forename: Go
authors.initials: G
authors.lastname: Wakabayashi
authors.forename: Masaru
authors.initials: M
authors.lastname: Miyazaki
authors.forename: Shinji
authors.initials: S
authors.lastname: Uemoto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Ohta
authors.forename: Ken
authors.initials: K
authors.lastname: Kikuchi
authors.forename: Tadatoshi
authors.initials: T
authors.lastname: Takayama
authors.forename: Hiroki
authors.initials: H
authors.lastname: Yamaue
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamamoto
authors.forename: Tadahiro
authors.initials: T
authors.lastname: Takada
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality* / Q000473:pathology*; D018572:Disease-Free Survival; D005260:Female; D006498:Hepatectomy; D006801:Humans; D007564:Japan; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000401:mortality* / Q000556:secondary* / Q000601:surgery; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D012955:Societies, Medical
keywords: Colorectal liver metastases; Hepatic resection; Optimal cut-off value of metastases