title: Long-term outcome of radiofrequency thermal ablation (RFA) of liver metastases from colorectal cancer (CRC): size as the leading prognostic factor for survival.
abstract: OBJECTIVE
  The aim of this study was to review some prognostic factors for survival after radiofrequency ablation (RFA) of metastases from colorectal cancer (CRC).
  
  
  METHODS
  From 1996 to 2009, 262 patients with metastases from CRC were treated with RFA. Fourteen were lost to follow-up. The following predictors were analysed in the remaining 248: synchronous/metachronous metastases, single/multiple metastases, diameter of largest metastasis and absence/presence of extrahepatic metastases. Survival was measured from the date of metastasis diagnosis and from the date of RFA.
  
  
  RESULTS
  Survival at 1, 2, 3 and 5 years was 93%, 78%, 62% and 35% from metastasis diagnosis, and 84%, 59%, 43% and 23% from the date of RFA. Median survival was 41 months in patients with largest metastasis ≤3 cm and 21.7 months for those with metastases >3 cm (p=0.0001); survival increased to 45.2 months in patients with largest metastasis ≤2.5 cm and fell to 18.5 months in those with metastasis >3.5 cm. Median survival of patients with extrahepatic metastases was significantly lower than that of patients without extrahepatic disease (23.3 vs. 32.6 months, p=0.018).
  
  
  CONCLUSIONS
  In light of our long-term results obtained with commonly used equipment, small lesion size (diameter of largest lesion ≤3 or 2.5 cm) proved to be the most favourable prognostic factor for survival in patients with CRC metastases to the liver treated with RFA. This conclusion is probably related to the possibility of obtaining radical ablation and points to the usefulness of devices allowing ablation of larger volumes. In the presence of extrahepatic metastases, RFA has less impact on survival, even though it is potentially useful in patients at a higher risk of death due to hepatic rather than extrahepatic metastases.
authors.affiliation: Istituto di Radiologia, Università di Torino, Facoltà San Luigi Gonzaga, Regione Gonzole 10, 10043, Orbassano Torino, Italy. andrea.veltri@unito.it
authors.forename: A
authors.initials: A
authors.lastname: Veltri
authors.forename: T
authors.initials: T
authors.lastname: Guarnieri
authors.forename: C
authors.initials: C
authors.lastname: Gazzera
authors.forename: M
authors.initials: M
authors.lastname: Busso
authors.forename: F
authors.initials: F
authors.lastname: Solitro
authors.forename: G
authors.initials: G
authors.lastname: Fora
authors.forename: P
authors.initials: P
authors.lastname: Racca
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D017115:Catheter Ablation / Q000379:methods*; D016009:Chi-Square Distribution; D015179:Colorectal Neoplasms / Q000188:drug therapy / Q000473:pathology*; D005260:Female; D006498:Hepatectomy; D006801:Humans; D008113:Liver Neoplasms / Q000188:drug therapy / Q000556:secondary* / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015996:Survival Rate; D016896:Treatment Outcome