Systematic review and meta-analysis of local ablative therapies for resectable colorectal liver metastases.
INTRODUCTION
Local ablative therapies (LAT) have shown positive but heterogenous outcomes in the treatment of colorectal liver metastases (CRLM). The aim of this systematic review is to evaluate LAT and compare them with surgical resection.


METHODS
In accordance with PRISMA guidelines, Medline, EMBASE, Cochrane and Web of Science databases were searched for reports published before January 2019. We included papers assessing radiofrequency ablation (RFA), microwave ablation (MWA), cryoablation (CA) and electroporation (IRE) treating resectable CRLM with curative intention. We evaluated LAT related complications and oncological outcomes as tumour progression (LTP), disease-free survival (DFS) and overall survival (OS).


RESULTS
The literature search yielded 6767 records; 20 papers (860 patients) were included. No included studies related mortality with LAT. Median adverse events percentage was 7%: (8% RFA;7% MWA). Median 3y-DFS was 32% (24% RFA; 60% MWA); 5y-DFS was 27%: (18% RFA; 38.5% MWA). Median 3y-OS was 59% (60% RFA; 70% MWA; 34% CA), 5y-OS was 44.5% (43% RFA; 55% MWA; 20% CA). Surgical resection showed decreased LTP, improved DFS and OS than those reported with LAT, with RFA accounting for reduced 1y-DFS (RR 0.83, 95%CI 0.71-0.98), 3y-DFS (RR 0.5, 95%CI 0.33-0.76), 5y-DFS (RR 0.53, 95%CI 0.28-0.98) and 5y-OS (RR 0.76, 95%CI 0.58-0.98) in comparison with surgical resection.


CONCLUSIONS
Low quality evidence suggests that both RFA and MWA seem superior to CA. MWA presents similar adverse events when compared to RFA with a possible increase in DFS and OS. Surgical resection still seems to provide superior DFS and OS in comparison with LAT.
['Di Martino|Marcello|M|', 'Rompianesi|Gianluca|G|', 'Mora-Guzmán|Ismael|I|', 'Martín-Pérez|Elena|E|', 'Montalti|Roberto|R|', 'Troisi|Roberto I|RI|']
D055011:Ablation Techniques D002277:Carcinoma D015179:Colorectal Neoplasms D003452:Cryosurgery D018450:Disease Progression D018572:Disease-Free Survival D018274:Electroporation D006801:Humans D008113:Liver Neoplasms D000078703:Radiofrequency Ablation D015996:Survival Rate D016896:Treatment Outcome
Colorectal liver metastases Radiofrequency ablation Microwave ablation Liver resection