摘要Background:Transcatheter arterial chemoembolization(TACE)combined with ablation has better clinical outcomes than monotherapy in patients with hepatocellular carcinoma(HCC).However,prolonged time intervals can lead to recanalization and neoangiogenesis,which may interfere with the synergistic effects of combination therapy.This study aimed to investigate whether TACE simultaneously combined with microwave ablation(MWA)is more effective than sequential therapy in patients with HCC.Methods:A total of 129 HCC patients who underwent TACE combined with MWA were included in this study.Based on the time interval between the first combination therapy of TACE and MWA,patients were divided into the simultaneous and sequential groups.Propensity score matching(PSM)was performed to reduce bias between the groups.Overall survival(OS),time-to-progression(TTP),tumor response,and liver function were compared.Results:Before PSM,the simultaneous group had a higher tumor load.Following PSM,36 and 40 patients remained in the simultaneous and sequential groups,respectively.The median TTP and OS were 12.9 vs.10.6 months(P=0.262)and 44.0 vs.26.5 months(P=0.313)for the simultaneous and sequential groups,respectively.After 4-8 weeks,there were 16 complete responders and 17 partial responders in the simultaneous group and 15 and 22 patients in the sequential group,respectively(P=0.504).The median complete response duration was 11.3 and 9.2 months for the simultaneous and sequential groups,respectively(P=0.882).These results did not differ in BCLC stratified subgroups.Patients with small tumor sizes(≤5 cm),tumor nodules ≤3,well-defined boundaries,and early-stage tumors were more likely to achieve complete response(all P＜0.05).After 4-8 weeks,the liver function was significantly improved compared to that before or one day after treatment.Conclusions:TACE simultaneously combined with MWA is safe and effective but not superior to sequen-tial therapy.