title: Patterns of recurrence after ablation of colorectal cancer liver metastases.
abstract: OBJECTIVE
  To determine the local recurrence rate and factors associated with recurrence after intraoperative ablation of colorectal cancer liver metastases.
  
  
  METHODS
  A retrospective analysis of a prospectively maintained database was performed for patients who underwent ablation of a hepatic colorectal cancer metastasis in the operating room from April 1996 to March 2010. Kaplan-Meier survival curves and Cox models were used to determine recurrence rates and assess significance.
  
  
  RESULTS
  Ablation was performed in 10% (n = 158 patients) of all cases during the study period. Seventy-eight percent were performed in conjunction with a liver resection. Of the 315 tumors ablated, most tumors were ≤ 1 cm in maximum diameter (53%). Radiofrequency ablation was used to treat most of the tumors (70%). Thirty-six tumors (11%) had local recurrence as part of their recurrence pattern. Disease recurred in the liver or systemically after 212 tumors (67%) were ablated. On univariate analysis, tumor size greater than 1 cm was associated with a significantly increased risk of local recurrence (hazard ratio 2.3, 95% confidence interval 1.2-4.5, P = 0.013). The 2 year ablation zone recurrence-free survival was 92% for tumors ≤ 1 cm compared to 81% for tumors >1 cm. On multivariate analysis, tumor size of >1 cm, lack of postoperative chemotherapy, and use of cryotherapy were significantly associated with a higher local recurrence rate.
  
  
  CONCLUSIONS
  Intraoperative ablation appears to be highly effective treatment for hepatic colorectal tumors ≤ 1 cm.
authors: Division of Hepatopancreatobiliary Surgery, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. kinghamt@mskcc.org
authors: T Peter
authors: TP
authors: Kingham
authors: Michael
authors: M
authors: Tanoue
authors: Anne
authors: A
authors: Eaton
authors: Flavio G
authors: FG
authors: Rocha
authors: Richard
authors: R
authors: Do
authors: Peter
authors: P
authors: Allen
authors: Ronald P
authors: RP
authors: De Matteo
authors: Michael
authors: M
authors: D'Angelica
authors: Yuman
authors: Y
authors: Fong
authors: William R
authors: WR
authors: Jarnagin
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017115:Catheter Ablation; D059186:Chemoradiotherapy, Adjuvant; D015179:Colorectal Neoplasms / Q000473:pathology*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000401:mortality / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009364:Neoplasm Recurrence, Local; D015996:Survival Rate