title: Frequency, risk factors and survival associated with an intrasubsegmental recurrence after radiofrequency ablation for hepatocellular carcinoma.
abstract: BACKGROUND
  In the treatment of hepatocellular carcinoma (HCC), hepatic resection has the advantage over radiofrequency ablation (RFA) in terms of systematic removal of a hepatic segment.
  
  
  METHODS
  We enrolled 303 consecutive patients of a single naïve HCC that had been treated by RFA at The University of Tokyo Hospital from 1999 to 2004. Recurrence was categorized as either intra- or extra-subsegmental as according to the Couinaud's segment of the original nodule. To assess the relationship between the subsegments of the original and recurrent nodules, we calculated the kappa coefficient. We assessed the risk factors for intra- and extra-subsegmental recurrence independently using univariate and multivariate Cox proportional hazard regression. We also assessed the impact of the mode of recurrence on the survival outcome.
  
  
  RESULTS
  During the follow-up period, 201 patients in our cohort showed tumor recurrence distributed in a total of 340 subsegments. Recurrence was categorized as exclusively intra-subsegmental, exclusively extra-subsegmental, and simultaneously intra- and extra-subsegmental in 40 (20%), 110 (55%), and 51 (25%) patients, respectively. The kappa coefficient was measured at 0.135 (95% CI, 0.079-0.190; P<0.001). Multivariate analysis revealed that of the tumor size, AFP value and platelet count were all risk factors for both intra- and extra-subsegmental recurrence. Of the patients in whom recurrent HCC was found to be exclusively intra-subsegmental, extra-subsegmental, and simultaneously intra- and extra-subsegmental, 37 (92.5%), 99 (90.8%) and 42 (82.3%), respectively, were treated using RFA. The survival outcomes after recurrence were similar between patients with an exclusively intra- or extra-subsegmental recurrence.
  
  
  CONCLUSIONS
  The effectiveness of systematic subsegmentectomy may be limited in the patients with both HCC and chronic liver disease who frequently undergo multi-focal tumor recurrence.
authors.affiliation: Department of Gastroenterology, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan. tateishi-tky@umin.ac.jp
authors.forename: Ryosuke
authors.initials: R
authors.lastname: Tateishi
authors.forename: Shuichiro
authors.initials: S
authors.lastname: Shiina
authors.forename: Masaaki
authors.initials: M
authors.lastname: Akahane
authors.forename: Jiro
authors.initials: J
authors.lastname: Sato
authors.forename: Yuji
authors.initials: Y
authors.lastname: Kondo
authors.forename: Ryota
authors.initials: R
authors.lastname: Masuzaki
authors.forename: Hayato
authors.initials: H
authors.lastname: Nakagawa
authors.forename: Yoshinari
authors.initials: Y
authors.lastname: Asaoka
authors.forename: Tadashi
authors.initials: T
authors.lastname: Goto
authors.forename: Kuni
authors.initials: K
authors.lastname: Otomo
authors.forename: Masao
authors.initials: M
authors.lastname: Omata
authors.forename: Haruhiko
authors.initials: H
authors.lastname: Yoshida
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Koike
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000453:epidemiology* / Q000601:surgery*; D017115:Catheter Ablation; D005260:Female; D006801:Humans; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000453:epidemiology* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000453:epidemiology* / Q000601:surgery*; D012307:Risk Factors; D016019:Survival Analysis; D013997:Time Factors; D016896:Treatment Outcome