To evaluate the impact of microvascular invasion (MVI) on the clinical prognosis of patients with single small liver cancer after hepatectomy.

Clinical data of 82 patients with single small liver cancer who underwent hepatectomy in the Affiliated Hospital of North Sichuan Medical College from January 2013 to June 2018 were retrospectively analyzed. Among them, 60 patients were male and 22 female, aged from 23 to 78 years, with a median age of 56 years. The informed consents of all patients were obtained and the local ethical committee approval was received. The diagnosis of MVI was made based on the pathological examination of surgical specimens. Clinicopathological features of MVI-positive patients were analyzed with Chi-square test. Survival analysis was conducted with Kaplan-Meier method and Log-rank test. Prognostic factors were identified by Cox proportional hazards regression model.

The positive rate of MVI in patients with single small liver cancer was 21%(17/82). The follow-up duration was ranged from 18 to 80 months, with a median duration of 61 months. During postoperative follow-up, liver cancer recurrence was observed in 25 cases and 13 cases died. Positive MVI was associated with preoperative AFP>20 μg/L, no tumor encapsulation, rough tumor margin and low tumor differentiation (χ²=5.102, 6.201, 10.686, 5.029; P<0.05). The 5-year overall survival rates were 47.1% and 83.1% in positive and negative MVI patients respectively, and the 5-year recurrence-free survival rates were 29.4% and 70.8%, where significant differences were observed (χ²=7.901, 10.623; P<0.05). Cox multivariate analysis showed that positive MVI was an independent risk factor for the postoperative overall survival and recurrence-free survival of patients (HR=3.595, 2.074; P<0.05).

The incidence of MVI in patients with single small liver cancer is relatively high. Positive MVI is an independent risk factor for the clinical prognosis. Higher recurrence rate and shorter overall survival are observed in patients with positive MVI.