Improved Outcomes of Thermal Ablation for Colorectal Liver Metastases: A 10-Year Analysis from the Prospective Amsterdam CORE Registry (AmCORE)

Abstract

Background: To analyze long-term oncological outcomes of open and percutaneous thermal ablation in the treatment of patients with colorectal liver metastases (CRLM).

Methods: This assessment from a prospective, longitudinal tumor registry included 329 patients who underwent 541 procedures for 1350 CRLM from January 2010 to February 2021. Three cohorts were formed: 2010-2013 (129 procedures [53 percutaneous]), 2014-2017 (206 procedures [121 percutaneous]) and 2018-2021 (206 procedures [135 percutaneous]). Local tumor progression-free survival (LTPFS) and overall survival (OS) data were estimated using the Kaplan-Meier method. Potential confounding factors were analyzed with uni- and multivariable Cox regression analyses.

Results: LTPFS improved significantly over time for percutaneous ablations (2-year LTPFS 37.7% vs. 69.0% vs. 86.3%, respectively, P < .0001), while LTPFS for open ablations remained reasonably stable (2-year LTPFS 87.1% [2010-2013], vs. 92.7% [2014-2017] vs. 90.2% [2018-2021], P = .12). In the latter cohort (2018-2021), the open approach was no longer superior regarding LTPFS (P = .125). No differences between the three cohorts were found regarding OS (P = .088), length of hospital stay (open approach, P = .065; percutaneous approach, P = .054), and rate and severity of complications (P = .404). The rate and severity of complications favored the percutaneous approach in all three cohorts (P = .002).

Conclusion: Over the last 10 years efficacy of percutaneous ablations has improved remarkably for the treatment of CRLM. Oncological outcomes seem to have reached results following open ablation. Given its minimal invasive character and shorter length of hospital stay, whenever feasible, percutaneous procedures may be favored over an open approach.

Keywords: Colorectal liver metastases (CRLM); Local tumor progression-free survival (LTPFS); Long-term oncological outcomes; Microwave ablation (MWA); Radiofrequency ablation (RFA).

Fig. 1

Flowchart of in- and excluded patients

Fig. 2

Kaplan–Meier survival curves indicating local tumor progression-free survival (LTPFS) per treated tumor (A) and per patient (B) after all thermal ablation sessions. Numbers at risk correspond to the amount of tumors and number of patients respectively. Death without local tumor progression (LTP) is censored (competing risk)

Fig. 3

Kaplan–Meier survival curves indicating the local tumor progression-free survival (LTPFS) per time frame. Analysis per treated tumor (A) and per patient (B). Time frames: 2010–2013; 2014–2017 and 2018–2021. Numbers at risk correspond to the amount of tumors and number of patients respectively. Overall comparison log-rank (Mantel–Cox) test is reported per graph. Death without local tumor progression (LTP) is censored (competing risk).

Fig. 4

Kaplan–Meier survival curves indicating local tumor progression-free survival (LTPFS) per time frame and approach. A, B Analysis of open and percutaneous thermal ablation per treated tumor and per patient respectively, C and D patients treated with open ablation, analysis per treated tumor and per patient respectively, E and F patients treated with percutaneous ablation, analysis per treated tumor and per patient respectively. Numbers at risk correspond to either the amount of tumors or the number of patients. Overall comparison log-rank (Mantel–Cox) test is reported per graph. Death without local tumor progression (LTP) is censored (competing risk)

Fig. 4

Kaplan–Meier survival curves indicating local tumor progression-free survival (LTPFS) per time frame and approach. A, B Analysis of open and percutaneous thermal ablation per treated tumor and per patient respectively, C and D patients treated with open ablation, analysis per treated tumor and per patient respectively, E and F patients treated with percutaneous ablation, analysis per treated tumor and per patient respectively. Numbers at risk correspond to either the amount of tumors or the number of patients. Overall comparison log-rank (Mantel–Cox) test is reported per graph. Death without local tumor progression (LTP) is censored (competing risk)

Fig. 4

Kaplan–Meier survival curves indicating local tumor progression-free survival (LTPFS) per time frame and approach. A, B Analysis of open and percutaneous thermal ablation per treated tumor and per patient respectively, C and D patients treated with open ablation, analysis per treated tumor and per patient respectively, E and F patients treated with percutaneous ablation, analysis per treated tumor and per patient respectively. Numbers at risk correspond to either the amount of tumors or the number of patients. Overall comparison log-rank (Mantel–Cox) test is reported per graph. Death without local tumor progression (LTP) is censored (competing risk)

Fig. 5

Kaplan–Meier survival curve of overall survival (OS) for patients treated with thermal ablation. Numbers at risk correspond to the number of patients