Comparisons of clinical patterns, short- and long-term prognostic outcomes in patients stratified by the severity of microvascular invasion after curative resection for hepatocellular carcinoma

Although microvascular invasion (MVI) is a robust pathological predictor of postoperative recurrence in hepatocellular carcinoma (HCC), the prognostic implications of MVI severity for both short- and long-term survival after curative resection remain a critical yet underexplored area. This study aimed to characterize the clinical patterns, short- and long-term prognosis of HCC patients stratified by MVI severity using the three-tiered MVI grading (MVI-TTG) system. We conducted a retrospective review of a database comprising patients who underwent curative resection for HCC between 2016 and 2023. Postoperative complications, overall survival (OS), and recurrence-free survival (RFS) were compared among the M0, M1, and M2 groups. Among the 243 patients included in the study, the distribution of MVI severities was as follows: M0 in 45.3%, M1 in 25.5%, and M2 in 29.2%. Compared to the M0 and M1 groups, the M2 group exhibited similar baseline characteristics but more advanced tumor burden. Regarding short-term outcomes, the incidence of major postoperative complications was comparable between the M2 group and the M0/M1 groups. In terms of long-term prognosis, the M2 group was independently associated with an increased risk of both postoperative recurrence and mortality, particularly within the first two years after surgery. Following propensity score matching (PSM), these prognostic outcomes remained consistent with those observed in the original cohort. Surgical resection remains a safe and feasible approach for HCC patients with severe MVI, which was identified as a strong and independent predictor of recurrence and mortality. Therefore, implementing intensified postoperative surveillance and exploring tailored adjuvant therapies are warranted to mitigate recurrence risk in this high-risk population.