Published online Mar 27, 2015. doi: 10.4240/wjgs.v7.i3.33
Peer-review started: September 12, 2014
First decision: November 27, 2014
Revised: January 8, 2015
Accepted: January 18, 2015
Article in press: January 20, 2015
Published online: March 27, 2015
Processing time: 201 Days and 13.2 Hours
AIM: To retrospectively evaluate the long-term survival of patients that received radiofrequency ablation (RFA) therapies of colorectal liver metastases.
METHODS: In 2005 to 2008, RFA of 105 colorectal liver metastases (CRLM) were performed on 49 patients in our institution. The liver metastases were evaluated, both before and after ablation therapies, with contrast enhanced computerised tomography and contrast enhanced ultrasonography. Histological evidence of malignant liver metastases was obtained in the few instances where contrast enhanced ultrasonography gave equivocal results. Accesses to the CRLM were guided ultrasonically in all patients. The data obtained from records of these ablations were retrospectively analysed and survival data were compared with existing studies in the literature.
RESULTS: 1-, 2-, 3-, 4- and 5-year survival rates, when no stringent selection criteria were applied, were 92%, 65%, 51%, 41% and 29% respectively. To explore the impact of the number and size of CRLM on patients’ survival, an exclusion of 13 patients (26.5%) with number of CRLM ≥ 5 and tumour size ≥ 40 mm resulted in 1-, 2-, 3-, 4- and 5-year survival rates improving to 94%, 69%, 53%, 42% and 31% respectively. It is of note that 9 of 49 patients developed extra-hepatic metastases, not visible or seen on pre-treatment scans, just after RFA treatment. These patients had poorer survival. The development of extra-hepatic metastases in nearly 20% of the patients included in our study can partly account for modestly lower survival rates as compared with earlier studies in the literature.
CONCLUSION: Our study underscores the fact that optimum patients’ selection before embarking on RFA treatment is vitally important to achieving a superior outcome.
Core tip: The current study corroborates the consensus in the literature which proposes that adequate patients’ selection before radiofrequency ablation (RFA) therapy is vitally important to achieving a satisfactory ablation success. To the best of our knowledge, the consensus proposed that patients with more than 5 hepatic metastases and tumour size of more than 40 mm are probably unsuitable for RFA. Furthermore, inadvertent inclusion of patients with extra-hepatic metastases for RFA treatment of colorectal liver metastases is an important factor that can influence negatively the overall patients’ survival.