Long-term survival analysis of microwave ablation for hepatocellular carcinoma comforming to the Milan crititia: primary versus recurrent HCC

Background: Whether microwave ablation (MWA) is as effective in initial hepatocellular carcinoma (IHCC) as in recurrent HCC (RHCC) is unclear.We aim to compare the long-term outcomes for IHCC and RHCC conforming to the Milan criteria. Methods In this retrospective study, 425 Milan-eligible patients (294 IHCCs, 131 RHCCs) who underwent MWA from January 2008 to November 2021 were included. All the patients with RHCC had MWA as initial treatment. Propensity-score matching (PSM) analysis was used to assess the overall survival (OS) and recurrence-free survival (RFS) between IHCC and RHCC. Results After PSM, OS in IHCC was better than in RHCC, with OS rates at 1, 3, 5, and 10 years in IHCC were 97.5%, 79.7%, 54.6% and 38.4%, respectively, and in RHCCs were 94.1%, 69.2%, 42.4% and 5.6%, respectively. However, subgroup analyses suggested that there were no significantly differences in OS between IHCC and RHCC in patients with solitary HCC ≤ 3.0 cm, AFP ≤ 200 ng/mL, or ALBI grade 1. Patients with RHCC had worse RFS than those with IHCC in the entire and PSM cohorts, as well as in the subgroup analyses. No association between time to recurrence with OS and RFS was identified in patients who received repeat MWA. Conclusions Although RHCC patients had worse prognosis than IHCC patients, MWA could be used as an effective treatment for RHCC as in patients with single small tumor, lower AFP level, and good liver function reserve regardless of time to recurrence. Close surveillance should be taken in RHCC patients after MWA.