Retrospective Study
Copyright ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastrointest Oncol. Sep 15, 2020; 12(9): 1044-1055
Published online Sep 15, 2020. doi: 10.4251/wjgo.v12.i9.1044
Oncological outcomes and predictors of radiofrequency ablation of colorectal cancer liver metastases
Chuan-Zhuo Wang, Guang-Xin Yan, He Xin, Zhao-Yu Liu
Chuan-Zhuo Wang, Guang-Xin Yan, He Xin, Zhao-Yu Liu, Department of Radiology, Shengjing Hospital of China Medical University, Shenyang 110004, Liaoning Province, China
Author contributions: Wang CZ and Liu ZY designed the research; Xin H and Yan GX performed the clinical research; Wang CZ, Xin H and Yan GX analyzed the data; Wang CZ and Liu ZY wrote the paper; all authors read and approved the final manuscript.
Supported by National Natural Science Foundation of China, No. 81470086 and No. 81871465.
Institutional review board statement: The study was reviewed and approved by the Medical Ethics Committee of Shengjing Hospital of China Medical University.
Informed consent statement: The patients were not required to give informed consent to the study because the analysis used anonymous clinical data that were obtained after each patient agreed to treatment by written consent.
Conflict-of-interest statement: The authors declare that there are no conflicts of interest related to this article.
Data sharing statement: No additional unpublished data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (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/
Corresponding author: Zhao-Yu Liu, MD, Chairman, Chief Doctor, Department of Radiology, Shengjing Hospital of China Medical University, No. 36 Sanhao Street, Heping District, Shenyang 110004, Liaoning Province, China. liushjh@163.com
Received: May 6, 2020
Peer-review started: May 6, 2020
Revised: June 21, 2020
Accepted: August 15, 2020
Article in press: August 15, 2020
Published online: September 15, 2020
Processing time: 126 Days and 17.9 Hours
Abstract
BACKGROUND

Surgical resection is considered the standard treatment option for long-term survival in colorectal cancer liver metastasis (CRLM) patients, but only a small number of patients are suitable for resection following diagnosis. Radiofrequency ablation (RFA) is an accepted alternative therapy for CRLM patients who are not suitable for resection. However, the relatively high rate of local tumor progression (LTP) is an obstacle to the more widespread use of RFA.

AIM

To determine the oncological outcomes and predictors of RFA in CRLM patients.

METHODS

A retrospective analyze was performed on the clinical data of 85 consecutive CRLM patients with a combined total of 138 liver metastases, who had received percutaneous RFA treatment at our institution from January 2013 to December 2018. Contrast-enhanced computed tomography was performed the first month after RFA to assess the technique effectiveness of the RFA and to serve as a baseline for subsequent evaluations. The Kaplan-Meier method was used to calculate overall survival (OS) and LTP-free survival (LTPFS). The log-rank test and Cox regression model were used for univariate and multivariate analyses to determine the predictors of the oncological outcomes.

RESULTS

There were no RFA procedure-related deaths, and the technique effectiveness of the treatment was 89.1% (123/138). The median follow-up time was 30 mo. The LTP rate was 32.6% (45/138), and the median OS was 36 mo. The 1-, 3-, and 5-year OS rates were 90.6%, 45.6%, and 22.9%, respectively. Univariate analysis revealed that tumor size and ablative margin were the factors influencing LTPFS, while extrahepatic disease (EHD), tumor number, and tumor size were the factors influencing OS. Multivariate analysis showed that tumor size larger than 3 cm and ablative margin of 5 mm or smaller were the independent predictors of shorter LTPFS, while tumor number greater than 1, size larger than 3 cm, and presence of EHD were the independent predictors of shorter OS.

CONCLUSION

RFA is a safe and effective treatment method for CRLM. Tumor size and ablative margin are the important factors affecting LTPFS. Tumor number, tumor size, and EHD are also critical factors for OS.

Keywords: Colorectal cancer liver metastasis; Radiofrequency ablation; Local tumor progression; Local tumor progression-free survival; Overall survival

Core Tip: Relatively high rate of local tumor progression (LTP) is an obstacle to more widespread use of radiofrequency ablation (RFA) in colorectal cancer liver metastasis (CRLM) patients. The purpose of this retrospective study was to determine the oncological outcomes and predictors of RFA in CRLM patients. The median overall survival (OS) of the 85 patients was 36 mo, and the rate of LTP was 32.6% in 138 lesions. Multivariate analysis showed that tumor size and ablative margin were independent predictors of LTP-free survival, while tumor number, tumor size, and extrahepatic disease were independent predictors of OS.