title: Two decades of experience with hepatic cryotherapy for advanced colorectal metastases.
abstract: BACKGROUND
  Only 15% of patients with colorectal liver metastases (CLM) are candidates for curative hepatectomy at time of diagnosis, limited by anatomical location and tumor burden. Ablative therapies may extend this. This study reports a single institution's long-term experience with hepatic cryotherapy for advanced CLM.
  
  
  METHODS
  Between April 1990 and June 2009, 304 patients were curatively treated with cryotherapy. Survival was estimated by Kaplan-Meier method. Prognostic factors for survivals were determined by using univariate and multivariate analyses.
  
  
  RESULTS
  A total of 293 patients were included into analysis. The median number of lesions treated per patient was three (range, 1-13). The median overall survival was 29 (range, 3-220) months. The 1-, 3-, 5-, and 10-year survivals were 87%, 41.8%, 24.2%, and 13.3%, respectively. A total of 161 patients developed intrahepatic recurrences: cryosite (23%); edge recurrence (14%); and within the liver remnant (78%). The median disease-free survival (DFS) was 9 (range, 1-220) months. The 1-, 3-, 5-, and 10-year DFS rates were 37.9%, 17.2%, 13.4%, and 10.8%, respectively. Univariate analysis identified four factors that significantly affect survival: node-positive primary tumor (p=0.001), preoperative CEA level (p<0.001), number of lesions (p<0.001), and use of neoadjuvant chemotherapy (p<0.001). However, only primary tumor nodal status was independently prognostic (hazards ratio=2.023; 95% confidence interval, 1.444-2.835; p<0.001).
  
  
  CONCLUSIONS
  Hepatic cryotherapy seems to be a safe and effective ablative technique for the treatment of colorectal liver metastases and may offer long-term survival in otherwise unresectable disease.
authors.affiliation: Hepatobiliary and Surgical Oncology Unit, Department of Surgery, St George Hospital, University of New South Wales, Sydney, NSW, Australia.
authors.forename: Keh M
authors.initials: KM
authors.lastname: Ng
authors.forename: Terence C
authors.initials: TC
authors.lastname: Chua
authors.forename: Akshat
authors.initials: A
authors.lastname: Saxena
authors.forename: Jing
authors.initials: J
authors.lastname: Zhao
authors.forename: Francis
authors.initials: F
authors.lastname: Chu
authors.forename: David L
authors.initials: DL
authors.lastname: Morris
mesh_terms: D015179:Colorectal Neoplasms / Q000517:prevention & control* / Q000556:secondary*; D003452:Cryosurgery; D018572:Disease-Free Survival; D005260:Female; D006498:Hepatectomy / Q000401:mortality; D006801:Humans; D053208:Kaplan-Meier Estimate; D008113:Liver Neoplasms / Q000401:mortality / Q000601:surgery*; D008175:Lung Neoplasms / Q000556:secondary; D008297:Male; D008875:Middle Aged; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local; D010534:Peritoneal Neoplasms / Q000556:secondary; D011379:Prognosis; D015996:Survival Rate