title: Radiofrequency ablation of hepatocellular carcinoma sized > 3 and ≤ 5 cm: is ablative margin of more than 1 cm justified?
abstract: OBJECTIVE
  To investigate whether an ablative margin (AM) > 1.0 cm might reduce chance of recurrence for patients with hepatocellular carcinoma (HCC) tumors 3.1 to 5.0 cm in size, compared with an AM of 0.5-1.0 cm.
  
  
  METHODS
  From October 2005 to December 2012, 936 consecutive patients with HCC who received radiofrequency ablation were screened. Of these, 281 patients, each with a single primary HCC tumor of 3.1 to 5.0 cm in size on its greatest diameter, were included in the study. Based on the AM width, we categorized patients into the 0.5-1.0 cm group and the > 1.0 cm group. Local tumor progression (LTP)-free survival, intrahepatic distant recurrence (IDR)-free survival and overall survival (OS) rates were obtained using the Kaplan-Meier method.
  
  
  RESULTS
  The 1-, 2-, 3-, 4-, and 5-year LTP-free survival rates and IDR-free survival rates were significantly higher in the > 1.0 cm group compared with the 0.5-1.0 cm group (97.5%, 86.3%, 73.6%, 49.5% and 26.4% vs 91.3%, 78.4%, 49.5%, 27.8%, and 12.8%; 95.1%, 90.3%, 77.0%, 61.0% and 48.3% vs 95.2%, 85.9%, 62.6%, 47.2% and 28.5%; P < 0.05). The 1-, 2-, 3-, 4-, and 5-year OS rates were 98.6%, 91.5%, 69.2%, 56.0% and 42.2%, respectively, in the 0.5-1.0 cm group and 100%, 98.9%, 90.1%, 68.7% and 57.4%, respectively, in the > 1.0 cm group (P = 0.010). There were no significant differences in complication rates between the two groups. Both univariate and multivariate analyses identified AM as an independent prognostic factor linked to LTP, IDR, and OS.
  
  
  CONCLUSIONS
  For HCC tumors > 3.0 cm and ≤ 5.0 cm, AM > 1.0 cm could reduce chances of recurrence compared with AM of 0.5-1.0 cm, emphasizing the need for a more defensive strategy using AMs > 1.0 cm for ablating HCC tumors of 3.1 to 5.0 cm.
authors.affiliation: Shan Ke, Xue-Mei Ding, Wen-Bing Sun, Department of Hepatobiliary Surgery, Chao-yang Hospital Affiliated to Capital Medical University, Beijing 100043, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Ke
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Ding
authors.forename: Xiao-Jun
authors.initials: XJ
authors.lastname: Qian
authors.forename: Yi-Ming
authors.initials: YM
authors.lastname: Zhou
authors.forename: Bao-Xin
authors.initials: BX
authors.lastname: Cao
authors.forename: Kun
authors.initials: K
authors.lastname: Gao
authors.forename: Wen-Bing
authors.initials: WB
authors.lastname: Sun
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006528:Carcinoma, Hepatocellular / Q000401:mortality / Q000556:secondary / Q000601:surgery*; D017115:Catheter Ablation / Q000009:adverse effects; D018572:Disease-Free Survival; D005260:Female; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000401:mortality / Q000473:pathology / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009364:Neoplasm Recurrence, Local / Q000517:prevention & control; D018365:Neoplasm, Residual; D016016:Proportional Hazards Models; D011446:Prospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D047368:Tumor Burden; D055815:Young Adult
keywords: Ablative margin; Hepatocellular carcinoma; Radiofrequency ablation; Recurrence; Survival