Transarterial Chemoembolization Monotherapy Versus Combined Transarterial Chemoembolization-microwave Ablation Therapy For Hepatocellular Carcinoma:a Propensity Analysis At A Single Center

Purpose:To compare the effectiveness of transarterial chemoembolization(TACE)combined with microwave ablation(MWA)(hereafter,TACE-MWA)with TACE for treating hepatocellular carcinomas(HCCs).Materials and Methods:Data of patients diagnosed with HCC treated by TACE-MWA or TACE from June 2014 to December 2015 were reviewed.Patients were classified into two study cohorts according to tumor size(cohort 1:tumor size>5 cm and cohort 2:tumor size<= 5 cm).Propensity score matching of patients was conducted.The outcomes of TACE-MWA were compared with those of TACE.In cohort 1,data of 208 patients diagnosed with HCC treated by TACE-MWA(n=40)or TACE(n=168)were reviewed.Propensity score matching of patients in a ratio of 1:1 was conducted.The primary study end points was overall survival(OS).Secondary study end points were 1 months' tumor responses using modified Response Evaluation Criteria in Solid Tumors(mRECIST)criteria and decrease of AFP level.In cohort 2,data of 244 patients diagnosed with HCC treated by TACE-MWA or TACE were reviewed.Propensity score matching of patients in a ratio of 1:2 was conducted.The primary study end points were tumor responses including tumor necrosis rates after initial treatment,6 months' tumor responses using mRECIST criteria,and time to tumor progression(TTP).Secondary study end points were OS and re-intervention times.Results:In cohort 1,there were 31 paired patients in the TACE-MWA group and the TACE group,respectively.Our data analysis indicated that TACE-MWA was associated a significantly higher 0.5,1,1.5,2 and 2.5 year overall survival rates(96.8%,90.3%,86.8%,82.5%and 70.7%versus 77.4%,61.3%,53.6%,48.2%and 24.1%,p=0.011).The TACE-MWA group has better tumor responses using mRECIST criteria(P=0.001).Combined treatment decreased AFP level significantly.No severe complication was found in both groups.In cohort 2,there were 48 patients and 96 patients in the TACE-MWA group and the TACE group,respectively.After initial treatments,tumor necrosis rates was higher in the TACE-MWA group(92.1%(58/63)versus 46.3%(56/121),P<0.001).At 6 months' follow-up,the TACE-MWA group has better tumor responses using mRECIST criteria((CR+PR+SD)was 95.8%in TACE-MWA group versus 64.5%in TACE group,P<0.001).TACE-MWA favored TIP(P<0.001),although no significant difference was detected between two groups' OS(p=0.317).Combined treatment decreased re-TACE times from 1.90 to 0.52;re-MWA times from 0.22 to 0.17.Subgroup analysis also found that combined therapy favored TTP in patients with tumor not only<= 3 cm(P<0.001),but 3 to 5 cm(P = 0.004).Conclusion:Compared with TACE,TACE-MWA benefits patient's survival time and is more effective with regard to tumor responses for HCC>5 cm;TACE-MWA is more effective with regard to tumor responses for HCC<=5 cm.