Objective: To investigate the influence of hepatitis B virus (HBV) infection and antiviral treatment on the formation of microvascular invasion (MVI) in hepatocellular carcinoma.
Methods: The clinical and pathological data of 660 patients with hepatocellular carcinoma who underwent radical hepatectomy from January 2015 to December 2017 in Affiliated Hospital of Qingdao University were retrospectively analyzed. 
Results: In the 660 patients, the incidence of MVI was 46.8% (309/660). Results of univariate analysis showed that MVI formation was significantly related to positive HBsAg, detectable HBV DNA load, and whether or not underwent antiviral treatment, and was also associated with the age, sex, preoperative levels of AFP, tumor markers and liver function parameters, histological grade, the size and number of lesions, capsule integrity and presence or absence of satellite nodules (all P<0.05). In the HBV-related patients, the results of multivariate Logistic regression analysis showed that detectable HBV DNA load was an independent risk factor for MVI (OR=5.33, P<0.001), while antiviral therapy for more than half a year was an independent protective factor against MVI (OR=0.37, P=0.002), and other independent influential factors for MVI were included sex, AFP level, tumor diameter, histological grade, incomplete capsule and presence of satellite nodules (all P<0.05). In patients with severe MVI, the proportions of HBV infection, high detectable HBV DNA load (>100 IU/mL) and cases without antiviral treatment were significantly increased compared with those with mild or without MVI (all P<0.05), moreover, the proportion of cases with liver cirrhosis was increased in patients with mild MVI (80.0%).
Conclusion: HBV infection and HBV DNA level are independent factors for MVI formation in hepatocellular carcinoma and antiviral therapy may have a preventive effect against the formation of MVI.