title: Intrahepatic distant recurrence after radiofrequency ablation for a single small hepatocellular carcinoma: risk factors and patterns.
abstract: BACKGROUND
  The pathogenesis of frequent intrahepatic recurrence of hepatocellular carcinoma (HCC) after surgical resection or local ablation therapy remains uncertain. Risks and patterns of intrahepatic distant recurrence (IDR) of a single, primary HCC lesion after radiofrequency (RF) ablation were examined.
  
  
  METHODS
  Ninety patients with a single primary HCC lesion of less than 3 cm who had complete RF ablation were enrolled in the study. Risk factors for IDR and the patterns of IDR after RF ablation were analyzed.
  
  
  RESULTS
  The median follow-up was 37.4 months. IDR was observed in 44 (48.9%) patients. The cumulative rate of IDR was 10.4%, 52.5%, and 77.0% at 1, 3, and 5 years, respectively. Univariate analysis revealed that a pretreatment serum alpha-fetoprotein (AFP) level of > or =50 ng/ml (P = 0.0324), a des-gamma-carboxy prothrombin (DCP) level of > or =40 mAu/ml (P = 0.006), an ablative margin of <5 mm of the ablation zone (P = 0.0306), and a prothrombin time of <70% (P = 0.0188) were related to IDR. A multivariate stepwise Cox proportional hazards regression model revealed that pretreatment serum AFP and DCP level and the ablative margin were independent risk factors for IDR pretreatment. Serum DCP level > or = 40 mAu/ml (P = 0.025), local tumor progression (P = 0.011), and ablative margin < 5 mm (P = 0.024) were related to multiple IDR.
  
  
  CONCLUSIONS
  HCC patients with high serum AFP or DCP before RF ablation should be carefully followed up to monitor any IDR. A sufficient ablative margin in RF ablation for HCC is required to prevent IDR.
authors.affiliation: Department of Gastroenterology, Kitasato University East Hospital, 2-1-1 Asamizodai, Sagamihara, 228-8520, Japan.
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Okuwaki
authors.forename: Takahide
authors.initials: T
authors.lastname: Nakazawa
authors.forename: Akitaka
authors.initials: A
authors.lastname: Shibuya
authors.forename: Koji
authors.initials: K
authors.lastname: Ono
authors.forename: Hisashi
authors.initials: H
authors.lastname: Hidaka
authors.forename: Masaaki
authors.initials: M
authors.lastname: Watanabe
authors.forename: Shigehiro
authors.initials: S
authors.lastname: Kokubu
authors.forename: Katsunori
authors.initials: K
authors.lastname: Saigenji
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001650:Bile Duct Neoplasms / Q000097:blood / Q000453:epidemiology / Q000556:secondary*; D001653:Bile Ducts, Intrahepatic; D015415:Biomarkers / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood; D006528:Carcinoma, Hepatocellular / Q000097:blood / Q000453:epidemiology / Q000556:secondary*; D017115:Catheter Ablation / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D008113:Liver Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local; D016016:Proportional Hazards Models; D011498:Protein Precursors / Q000097:blood; D011516:Prothrombin; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D000509:alpha-Fetoproteins / Q000378:metabolism
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; D011498:Protein Precursors; D000509:alpha-Fetoproteins; C008208:acarboxyprothrombin; D011516:Prothrombin