ObjectiveTo explore the influence of 5 mm surgical margin (SM) width on the prognosis of patients with solitary hepatocellular carcinoma (HCC) and the influence of tumor size and microvascular invasion (MVI) on strategic decision of SM width.MethodsThe clinicopathologic data of patients with solitary HCC underwent the surgical resection in the West China Hospital of Sichuan University from January 2014 to September 2015 were collected. According to the inclusion and exclusion criteria of this study, the prognostic differences of the patients with SM≤5 mm and SM>5 mm were compared after the propensity score matching (PSM), and the influences of the 5 mm SM on the recurrence-free survival rate of large HCC (>5 cm) or small HCC (≤5 cm) and MVI positive or negative patients were analyzed.ResultsA total of 266 eligible patients were included, with a median overall survival of 40.01 months and a median recurrence-free survival of 37.01 months. During the follow-up period, 137 patients recurred and 75 patients died. After PSM, the basic indexes had no significant differences between the patients with SM>5 mm (n=78) and SM≤5 mm (n=78). The results of the multivariate Cox regression analysis showed that the tumor size and MVI were the important factors of the recurrence-free survival (P<0.05) and the tumor size, MVI, HBeAg, and alpha-fetoprotein (AFP) were the important factors of the overall survival (P<0.05) before the PSM; while the MVI and SM were the important factors of the recurrence-free survival (P<0.05), the gender, AFP, and MVI were the important factors of the overall survival (P<0.05) after the PSM. The recurrence-free survival rate of the patients with SM >5 mm had better than that with SM≤5 mm after the PSM, but the overall survival had no difference. In the MVI negative and large HCC subgroups, the patients with SM>5 mm showed the better recurrence-free survival rate. However, in the MVI positive and small HCC subgroups did not show any differences in the recurrence-free survival rate for the different SM widths.ConclusionsAccording to the results of this study, a wider SM (>5 mm) could improve recurrence-free survival in patients with a single tumor within BCLC stage 0/A. For patients without MVI or large HCC, SM>5 mm might be adequate. However, for patients with MVI or small HCC, the determination of an appropriate SM width needs further to be investigated.