The comparison of local tumor control after microwave ablation, surgical resection and combined treatment for colorectal liver metastases

Aim. We aimed to compare the local therapeutic efficiency of microwave ablation (MWA), surgical resection, and combined treatment, assess the outcomes, and identify predictive factors for local treatment response in colorectal liver metastases (CLMs). Methods. From March 2013 to September 2019, a total of 54 patients with 302 CLMs were enrolled in this retrospective study. Eleven patients (20.4%) were treated with MWA, 9 patients (16.7%) with surgery, and 34 patients (63%) with the combined method. Univariate and multivariate analyses were performed to investigate overall survival (OS) and hepatic progression-free survival (HPFS) using the Cox proportional hazard regression model. The logistic regression analysis was used to identify the predictive factors for the local treatment response. Results. Total treatment response was achieved in 46.3% (n=25) of the patients. Local tumor progression was seen in 7.4% (n=4) of the patients, and the rate of intrahepatic distal recurrence was 46.3% (n=25). There were no significant differences in HPFS and OS between the three groups (p=0.56 and 0.90, respectively). Younger age (<60), smaller (≤ 2 cm) or fewer (≤3) liver metastases, and wild-type RAS were predictive for higher rates of local treatment response (OR 0.22, 95% CI 0.15-0.93, p=0.04; OR 1.12, 95% CI 0.54-2.12, p=0.029; OR 1.37, 95% CI 0.97-2.37, p=0.035; OR 0.23, 95% CI 0.10-0.85, p=0.028, respectively). Conclusions. The results of this study reveal that the use of MWA, alone or combined with resection, may achieve high local treatment response and similar survival rates compared to patients undergoing resection, suggesting that MWA could potentially be preferred over surgical procedures.