The impact of resection margin and microvascular invasion on long-term prognosis after curative resection of hepatocellular carcinoma: a multi-institutional study

The resection margin (RM) status and microscopic vascular invasion (MVI) are known prognostic factors for hepatocellular carcinoma (HCC). An enhanced understanding of their impact on long-term prognosis is required to improve oncological outcomes.Using multi-institutional data, the different impact of the RM status (narrow,1 cm, or wide, ≥1 cm) and MVI (positive or negative) on overall survival (OS) and recurrence-free survival (RFS) after curative liver resection of solitary HCC without macrovascular invasion was analyzed.In 801 patients, 306 (38%) had a narrow RM and 352 (44%) had positive MVI. The median OS and RFS were 109.8 and 74.8 months in patients with wide RMnegative MVI, 93.5 and 53.1 months with wide RMpositive MVI, 79.2 and 41.6 months with narrow RMnegative MVI, and 69.2 and 37.5 months with narrow RMpositive MVI (both P 0.01). On multivariable analyses, narrow RMpositive MVI had the highest hazard ratio with reduced OS and RFS (HR 2.96, 95% CI 2.11-4.17, and HR 3.15, 95% CI, 2.09-4.67, respectively).Concomitant having narrow RM and positive MVI increases the risks of postoperative death and recurrence by about 2-fold in patients with solitary HCC.