Background and Aims: Studies have demonstrated that postoperative transarterial chemoembolization (TACE) may provide survival benefit in patients with hepatocellular carcinoma (HCC), especially those with high risk factors for recurrence. However, the definition of the patient populations benefited from this treatment remains controversial. Therefore, this study was conducted to investigate the clinical efficacy of microwave ablation-assisted liver resection combined with postoperative TACE in treatment of BCLC stage B HCC.  
Methods: The clinical data of HCC patients in BCLC stage B with 2 or 3 tumors, tumor maximum diameter >3 cm and positive microvascular invasion (MVI) undergoing microwave ablation-assisted liver resection from January 2010 to December 2014 in the Second Affiliated Hospital, Airforce Military Medical University were collected. The patients were divided into observation group and control group according to whether the postoperative TACE was performed. The survival analysis was performed by Kaplan-Meier method and the survival difference between the two groups was compared by Log-rank test. The factors affecting the prognosis of the patients were analyzed by Cox-proportional hazard regression model. 
Results: A total of 344 eligible patients were enrolled, of whom, 173 cases received postoperative TACE (observation group) and 171 cases did not undergo postoperative TACE (control group). The baseline data were comparable between the two groups of patients. The 1-, 3- and 5-year overall survival rates (OS) were 82.7%, 47.4% and 28.8% for observation group, and were 69.0%, 22.3% and 15.9% for control group; the 0.5-, 1- and 3-year disease-free survival rates (DFS) were 87.6%, 75.0% and 29.6% for observation group, and were 73.8%, 60.4% and 10.6% for control group, respectively. Both OS and DFS in observation group were significantly better than those in control group (both P<0.001). The results of univariate and multivariate analysis showed that treatment method, tumor size, albumin, total bilirubin, platelet and HBsAg were associated with OS (P<0.05). The multivariate analysis demonstrated that treatment method, tumor size, albumin, total bilirubin and HBsAg were associated with DFS (all P<0.05).
Conclusion: Microwave ablation-assisted liver resection combined with postoperative TACE can offer significant survival benefit in patients in BCLC stage B with 2-3 tumors, tumor maximal diameter larger than 3 cm and positive MVI. However, this conclusion still needs to be verified by multi-center and high-quality studies with large sample size.