Efficacy Analysis of Capsule Integrity and TACE Combined with Microwave Ablation versus Microwave Ablation Alone for Primary Hepatocellular Carcinoma.

Background: Locoregional minimally invasive therapies have become important treatment options for patients with early- and intermediate-stage hepatocellular carcinoma (HCC). However, the integrity of the tumor pseudocapsule may influence the ablation margin and local tumor control achieved by microwave ablation (MWA), potentially contributing to heterogeneous treatment outcomes. This real-world study aimed to evaluate the efficacy and safety of transarterial chemoembolization (TACE) combined with MWA compared with MWA alone in HCC patients stratified according to pseudocapsule integrity. Methods: We retrospectively enrolled 68 patients with early-stage HCC who underwent MWA alone or TACE combined with MWA at our institution between May 2017 and December 2022. Propensity score matching (PSM) was performed to reduce baseline imbalances and selection bias. Patients were categorized into the TACE plus MWA group (T+M group) and the MWA-alone group (M group) according to the treatment modality. Based on preoperative imaging assessment, patients were further stratified into intact and incomplete pseudocapsule subgroups, and treatment outcomes were compared between the T+M and M groups within each subgroup. The primary endpoint was progression-free survival (PFS), and the secondary endpoint was safety. Results: After 1:1 PSM, no significant difference in median PFS was observed between the TACE plus MWA group and the MWA-alone group in the overall cohort. In the incomplete pseudocapsule subgroup, patients receiving TACE plus MWA demonstrated significantly longer median PFS than those receiving MWA alone (51.1 vs 10.4 months, P < 0.05). The 1-year and 3-year PFS rates were 85% and 62% in the T+M group, compared with 46% and 28% in the M group, respectively. Multivariable Cox regression analysis identified treatment modality as an independent prognostic factor for PFS in patients with incomplete pseudocapsules (hazard ratio [HR], 0.301; 95% confidence interval [CI], 0.094-0.962; P = 0.043). In the intact pseudocapsule subgroup, the median PFS was 52.1 months in the T+M group and was not reached in the M group, with no statistically significant difference observed between the groups (P > 0.05). No grade ≥3 treatment-related adverse events were observed in either group. Conclusion: In patients with early-stage HCC, TACE combined with MWA did not demonstrate a significant overall PFS benefit compared with MWA alone. However, among patients with incomplete pseudocapsules, the combination therapy was associated with prolonged PFS. These findings suggest that TACE combined with MWA may represent a potential treatment strategy for HCC patients with incomplete pseudocapsules, a subgroup characterized by a higher risk of recurrence.