Microwave Ablation Versus Surgical Resection For Hepatocellular Carcinoma Between 3 And 5 Cm

Background and Aim:Hepatocellular carcinoma(HCC)is now the fifth most common cancer and the second most frequent cause of cancer related mortality in China.Curative resection and thermal ablation represent two treatment options for HCC.However,surgical resection(SR)is always limited by insufficient postoperative hepatic reserve.Thermal ablation representing a less invasive procedure could be recommended as an alternative therapeutic option for these patients.For thermal ablation,radiofrequency ablation(RFA)and microwave ablation(MWA)are the two most commonly used modalities.Previous studies reported that RFA is inferior to SR for local tumor control and long-term patient survival in HCC above the 3 cm threshold.However,MWA has advantages over RFA in terms of ablation volume,temperature and operation time.The American Association for the Study of Liver Diseases(AASLD)and the European Association for the Study of the Liver(EASL)considered that MWA may treat the tumor larger than 3 cm in diameter more effectively than RFA.but it is not clear whether the curative effect of MWA as to hepatocellular carcinoma(HCC)is comparable to that of SR.We aimed to compare the outcomes of MWA with SR for patients with HCC less than 3 nodules and up to 5 cm in size and provide basis for treatment selection of these patients.Materials and Methods:393 patients treated for HCC up to 5 cm by MWA or SR were included from January 2010 to December 2017.Among these patients 93 patients received MWA and 300 patients received SR.Overall survival(OS),progression-free survival(PFS),complication and hospital stay of those patients were compared by using propensity score matching.To decrease the selection bias between the two study groups,we performed a 1:1 propensity score matching(PSM)to create a comparable control cohort,including age,sex,Child-Pugh class,presence of liver cirrhosis,model for end-stage liver disease(MELD)score,antiviral treatment,serum AFP,alanine aminotransferase level and aspartate aminotransferase level,presence of portal hypertension,primary tumor number and tumor size.After PSM，a new cohort comprising 80 patients in the MWA group and 80 patients in the SR group was generated for further analysis.Results:In the total cohort of HCC ranging from 3 to 5 cm,the OS rates at 1,3,and 5 years were 91.3%,78.5%,and 64.6%in the MWA group,compared to 95.4%,82.5%,and 65.8%in the SR group,respectively(p=0.548).The 1-,3-,and 5-years PFS rates were 61%,33.5%,and 29.8%in the MWA group,and 67.6%,43.9%,and 31.4%in the SR group,respectively(p=0.306).In the PSM cohort of HCC ranging from 3 to 5cm,the 1-,3-,and 5-years OS rates were 90.3%,79.7%,and 65.5%in the MWA group,and 96.7%,88.6%,and 71%in the SR group,respectively(p=0.457).The 1-,3-,and 5-years PFS rates were 63.6%,36.8%,and 32.7%in the MWA group,and 74.2%,41.9%,and 35.5%in the SR group,respectively.In the total cohort of HCC up to 5cm,the OS rates at 1,3,and 5 years were 90.1%,82.9%and 71.9%in the MWA group,compared to 95.5%,86.1%and 67.6%in the SR group,respectively(p=0.879).The 1-,3-,and 5-years PFS rates were 66.3%,46.1%,and 33.7%in the MWA group,and 71.8%,44.3%,and 31.8%in the SR group,respectively(p=0.932).In the PSM cohort,the 1-,3-,and 5-years OS rates were 89.9%,86.6%,and 74.0%in the MWA group,and 98.6%;89.4%,and 71.6%%in the SR group,respectively(p=0.965).The 1-,3-and 5-years PFS rates were 68.8%,50.7%and 38.7%in the MWA group,and 77.7%,49.6%and 35.7%in the SR group,respectively(p=0.801).Besides,in the MWA group,the cumulative local tumor progression rates of HCCs between 3 and 5 cm were similar to those of HCCs up to 3 cm(6.3%versus 7.1%at 1 years,9.7%versus 9.2%at 2 years,p=0.954),The MWA group showed fewer complications(55%versus 78.8%,p=0.041)and shorter hospital stay(8 days versus 15 days,p<0.001)compared with the SR group.Conclusion and Significance:MWA is a safe and effective locoregional ablation modality.MWA showed similar survival outcomes compared with SR for HCCs up to 5 cm.However,it showed favorable results in terms of complication rate and hospital stay compared to SR.The current study aimed to compare the efficacy between MWA group and SR group and provide basis for treatment selection of patients with HCCs.