This study aimed to identify the preoperative predictors of microvascular invasion (MVI) in solitary small hepatocellular carcinoma (HCC) and evaluate their application in surgical treatment.

We retrospectively analyzed 161 patients with solitary small HCC who underwent curative hepatic resection. Overall and disease-free survival rates were calculated by Kaplan-Meier method and compared by log-rank test. The independent predictors were identified by Cox proportional hazards model.

MVI was an independent predictor of both overall and disease-free survival. In 51 patients with MVI, anatomic resection achieved better survival than non-anatomic resection. However, anatomic resection and non-anatomic resection brought similar survival in patients without MVI. Alpha-fetoprotein (AFP) was identified as the unique predictor of MVI (HR=2.773, p=0.004). Anatomic resection achieved better survival outcome than non-anatomic resection when AFP >100μg/L (5-year overall survival rate: 85% vs. 55%, p=0.024; 5-year disease-free survival rate: 37% vs. 21%, p=0.025), while there was no statistical survival difference between anatomic and non-anatomic resection when AFP <=100μg/L (5-year overall survival rate: 85% vs. 76%, p=0.838; 5-year disease-free survival rate: 48% vs. 49%, p=0.921).

Compared with non-anatomic resection, anatomic hepatic resection improves overall and disease-free survival of solitary small HCC patients with AFP >100μg/L.