Thermal ablation versus hepatectomy for solitary colorectal liver metastases up to 5 cm: a multicenter target trial emulation on safety, efficacy, and cost-effectiveness.

Abstract

No randomized trials or large-scale observational studies directly compared thermal ablation (TA) and hepatectomy (HT) for solitary colorectal liver metastases (SCLM) ≤ 5 cm with long-term follow-up. In this multicenter target trial emulation (2009-2024), 1,334 patients with SCLM ≤ 5 cm from 21 Chinese hospitals were enrolled. Propensity score matching (1:1) balanced baseline characteristics, yielding 437 matched pairs. Primary and secondary endpoints were progression-free survival (PFS) and overall survival (OS), respectively. Complications, hospital stay, and costs were analyzed. Sensitivity analyses were performed to evaluate the robustness of the results. After matching, median PFS was 1.81 years (95% CI 1.60-2.04) for TA vs 1.95 years (1.67-2.34) for HT (HR 0.94, 95% CI 0.82-1.09; P = 0.41). Median OS was 7.22 years (6.43-9.05) for TA vs 8.09 years (6.68-10.58) for HT (HR 0.89, 0.71-1.11; P = 0.30). The Five-year PFS and OS rates were comparable between groups. The PFS rates were 30.05% (95% CI: 25.32%-35.67%) for TA and 32.16% (95% CI: 27.49%-37.63%) for HT, while OS rates were 62.36% (95% CI: 56.24%-69.14%) for TA and 67.79% (95% CI: 62.38%-73.66%) for HT. TA reduced Clavien-Dindo III-IV complications (2.1% vs 5.0%; P = 0.017), hospital stay (median 3 vs 10 days; P < 0.001), and costs (median $4,820 vs $10,239; P < 0.001). Across all predefined subgroups (e.g., tumor size, CRS), treatment with TA resulted in PFS and OS comparable to those achieved with HT. For SCLM ≤ 5 cm, TA provides comparable oncologic outcomes to HT, alongside superior safety and cost-effectiveness. This supports its role as a first-line therapeutic alternative for selected patients or when surgery is contraindicated.