Is microwave ablation therapy as effective as colorectal liver metastases in noncolorectal liver metastases?

BACKGROUND/AIM: The aim of the study was to evaluate the relationship between primary tumor type and the effectiveness of microwave ablation (MWA) therapy by comparing the technical and clinical outcomes of MWA in the treatment of colorectal liver metastases (CLM) and noncolorectal liver metastases (NCLM). MATERIALS AND METHODS: Between January 2019 and March 2021, 47 consecutive patients (25 male, 22 female) with a total of 63 unresectable hepatic metastases underwent MWA under ultrasound guidance. The patients were divided into CLM (n = 29) and NCLM (n = 18) groups. Patient demographics, procedural details, and complications were noted. The overall survival (OS) and disease-free survival (DFS) rates were also analyzed. RESULTS: Technical success was 100% in both groups. No major complication was observed. Three minor complications [fatigue (n = 2) and subcutaneous hematoma (n = 1)] were encountered. DFS rates were 88.9%, 71.9%, 64.9%, and 44.0% at 3, 6, 12, and 24-months, respectively, with a mean DFS of 17.4 months (95% CI: 15.1, 19.7). Also, OS rates were 93.7%, 90.0%, 76.8%, and 64.3%, at 3, 6, 12, and 24-months, respectively, with a mean OS of 18.5 months (95% CI: 16.2, 20.7). There was no significant difference in recurrence between the CLM and NCLM groups (p = 0.452). The recurrence rate in liver metastases > 3 cm in size was significantly higher than in metastases ≤ 3 cm in size (p < 0.001). CONCLUSIONS: MWA therapy is as effective in the NCLM group as in the CLM group, regardless of histologic type. Metastasis size (>3 cm) was correlated with the recurrence rate in the CLM and NCLM groups.