Long-Term Outcomes of Interventional Treatments for Lung Cancer Liver Metastases: Transarterial Chemoembolization and Microwave Ablation

Purpose: The aim of this study was to evaluate the long-term results of transarterial chemoembolization (TACE) and microwave ablation (MWA) as locoregional interventional treatments for lung cancer liver metastases (LCLM) in different protocols and settings. Material and Methods: A total of 56 patients (31 males and 25 females; mean age 59.1 ± 9.8 years) with LCLM were included in our retrospective study, conducted at our department between 2009 and 2024. These patients had undergone different therapies and were divided into two groups depending on the treatment protocol. Twenty-six patients (13 women and 13 men; mean age: 56.8 ± 11.7 years) with 49 tumors were solely treated by TACE, who underwent 77 sessions. A total of thirty patients (18 males and 12 females; mean age 61.2 ± 7.3 years) with 48 tumors were in the ablation-based group (TACE + MWA or MWA-only), who underwent 94 TACE and 53 MWA treatment sessions. Results: The ablation-based group exhibited significantly longer overall survival than the TACE-only group, achieving a median Overall Survival (mOS) of 1.6 years (95% CI: 1.1–2.1) versus 0.5 years (95% CI: 0.2–0.9) for the TACE-only group (Log-Rank χ2 = 12.17, p < 0.001). The survival rates at 1-, 3-, and 5-years were 70%, 23% and 8% for the ablation group, respectively, compared to 20%, 10%, and 0% for the TACE monotherapy group, in which no patient survived beyond 4.5 years. In a multivariable Cox model adjusted for histological subtype, number of lesions, and maximum lesion diameter, TACE monotherapy remained independently associated with mortality (hazard ratio [HR]: 2.711, 95% CI: 1.363–5.391, p = 0.004). With respect to neoadjuvant chemosensitivity, a per-lesion analysis revealed no statistically significant difference in tumor downsizing between Gemcitabine-based (12.6%) and Irinotecan-based (19.7%) regimens (p = 0.452). No major procedure-related complications or treatment-related deaths were identified in the available records across 224 treatment sessions. Conclusions: The ablation-based cohort exhibited significantly longer overall survival than the TACE monotherapy group, and the treatment group remained independently associated with survival after adjustment. Because treatment allocation followed hepatic tumor burden rather than randomization, this association is subject to confounding by indication and is interpreted accordingly. TACE was effective as a neoadjuvant downsizing modality with either chemotherapeutic combination, although the two were applied in different periods and were therefore not compared under equivalent conditions. These findings support the further evaluation of ablation-containing treatment strategies in appropriately selected patients and require confirmation in larger prospective studies.