Editorial
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Apr 7, 2016; 22(13): 3511-3515
Published online Apr 7, 2016. doi: 10.3748/wjg.v22.i13.3511
Thermal ablation in colorectal liver metastases: Lack of evidence or lack of capability to prove the evidence?
Sergio Sartori, Paola Tombesi, Francesca Di Vece
Sergio Sartori, Paola Tombesi, Francesca Di Vece, Section of Interventional Ultrasound, St Anna Hospital, 44100 Ferrara, Italy
Author contributions: Sartori S, Tombesi P and Di Vece F equally contributed to this paper with conception; and design of the study, literature review and analysis, drafting and critical revision and editing, and final approval of the final version.
Conflict-of-interest statement: No potential conflicts of interest relevant to this article were reported.
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: Sergio Sartori, MD, Section of Interventional Ultrasound, St Anna Hospital, via A. Moro 8, 44100 Ferrara, Italy. srs@unife.it
Telephone: +39-532-239480 Fax: +39-532-239613
Received: November 10, 2015
Peer-review started: November 11, 2015
First decision: December 11, 2015
Revised: December 22, 2015
Accepted: January 11, 2016
Article in press: January 11, 2016
Published online: April 7, 2016
Abstract

Many studies suggest that combined multimodality treatments including ablative therapies may achieve better outcomes than systemic chemotherapy alone in patients with colorectal liver metastases. Nevertheless, ablative therapies are not yet considered as effective options because their efficacy has never been proved by randomized controlled trials (RCT). However, there are in literature no trials that failed in demonstrating the effectiveness of ablative treatments: what are lacking, are the trials. All the attempts to organize phase III studies on this topic failed as a result of non accrual. Just one prospective RCT comparing radiofrequency ablation combined with systemic chemotherapy vs chemotherapy alone has been published. It was designed as a phase III study, but it was closed early because of slow accrual, and was downscaled to phase II study, with the consequent limits in drawing definite conclusions on the benefit of combined treatment. However, the combination treatment met the primary end point of the study and obtained a significantly higher 3-year progression-free survival than systemic chemotherapy alone. It is very unlikely that ultimate efficacy of ablation treatments will ever be tested again, and the best available evidence points toward a benefit for the combination strategy using ablative treatments and chemotherapy.

Keywords: Liver metastases, Colorectal cancer, Thermal ablation, Radiofrequency ablation, Microwave ablation, Laser ablation, Systemic chemotherapy

Core tip: Phase III randomized controlled trials (RCT) on the efficacy of thermal ablation combined with systemic chemotherapy in colorectal liver metastases are lacking in literature, and it is very unlikely that ultimate efficacy of ablation treatments will ever be tested again by RCT because of the difficult accrual. However, the best available evidence points toward a benefit for the combination strategy using ablative treatments and chemotherapy.