Does microvascular invasion in Barcelona Clinic Liver Cancer stage A multinodular hepatocellular carcinoma indicate early-stage behavior?

Background: To identify the impact of tumor number on Barcelona Clinic Liver Cancer (BCLC) early-stage hepatocellular carcinoma (HCC) and the impact of microvascular invasion (MVI) on multinodular HCC (MHCC). Methods: We retrospectively analyzed 1,548 patients who had early-stage HCC [solitary HCC (SHCC, n=1,481) and MHCC (n=67)], according to the BCLC classification, after curative resection. Recurrence-free survival (RFS) and overall survival (OS) were compared. Propensity score matching (PSM) was used to balance potential confounding factors. Results: Both before and after PSM, significant differences were noted between the MHCC group and the SHCC group in RFS but not in OS. For the PSM cohort, the 5-year RFS rates were 7.5% and 41.2% for the MVI-positive MHCC group and the SHCC group, respectively (P<0.001). The 5-year OS rates were 48.9% and 75.2% for the MVI-positive MHCC group and the SHCC group, respectively (P=0.017). The RFS and OS were not significantly different between the MVI-negative MHCC group and the SHCC group. MVI (P=0.029) and multiple nodules (P=0.029) were associated with early recurrence. Conclusions: The presence of MVI in BCLC early-stage MHCC was highly suggestive of a poor prognosis and should not be classified as early-stage biological behavior.