Retrospective Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Surg. Mar 27, 2015; 7(3): 33-38
Published online Mar 27, 2015. doi: 10.4240/wjgs.v7.i3.33
Long-term survival following radiofrequency ablation of colorectal liver metastases: A retrospective study
Simeon Niyi Babawale, Thomas Mandøe Jensen, Jens Brøndum Frøkjær
Simeon Niyi Babawale, Thomas Mandøe Jensen, Jens Brøndum Frøkjær, Department of Radiology, Aalborg University Hospital, DK-9000 Aalborg, Denmark
Jens Brøndum Frøkjær, Department of Clinical Medicine, Aalborg University, DK-9000 Aalborg, Denmark
Author contributions: Babawale SN analysed the data and prepared the manuscript; Jensen TM contributed to the conduct of the study; Frøkjær JB participated in the study design and contributed to manuscript preparation.
Supported by Department of Radiology, Aalborg University Hospital, Aalborg, Denmark.
Ethics approval: N/A.
Informed consent: N/A.
Conflict-of-interest: None.
Data sharing: Raw dataset is available from the corresponding author at jebf@rn.dk.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Jens Brøndum Frøkjær, MD, PhD, Associate Professor, Department of Radiology, Aalborg University Hospital, Hobrovej 18-22, DK-9000 Aalborg, Denmark. jebf@rn.dk
Telephone: +45-97-665105 Fax: +45-99-326507
Received: September 11, 2014
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
Abstract

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.

Keywords: Colorectal cancer, Liver metastasis, Radiofrequency ablation, Long-term survival, Ablation success

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.