The impact of microvascular invasion in tumor recurrence and survival after liver resection for non-B non-C hepatocellular carcinoma: a multicenter, propensity score-matched analysis.

BACKGROUND

The epidemiological shift toward non-B non-C hepatocellular carcinoma (NBNC-HCC) highlights the need for identifying prognostic markers in this population. While microvascular invasion (MVI) has been established in hepatitis virus-related HCC (HV-HCC), its role in NBNC-HCC remains unclear.

METHODS

This multicenter retrospective study analyzed 3308 patients with HCC undergoing curative resection (2012-2023). Risk factors for MVI were identified using logistic regression in the overall cohort. From this cohort, 439 patients with NBNC-HCC were stratified based on the MVI status and balanced using propensity score matching (PSM). Cox regression models and Kaplan-Meier analysis with log-rank test were employed to compare recurrence-free survival (RFS) and overall survival (OS) between MVI-positive and MVI-negative subgroups.

RESULTS

The incidence of MVI was lower in the NBNC-HCC group compared to the HV-HCC group (31.44% vs. 38.06%, P = 0.007), but viral hepatitis was not an independent risk factor for MVI (OR = 1.20, 95% CI 0.95-1.51, P = 0.118). After PSM, patients with MVI-positive NBNC-HCC had significantly worse RFS (median 30.0 vs. 47.0 months) and OS (median 41.0 months vs. not reached) compared to MVI-negative patients (both P < 0.01). MVI independently predicted postoperative recurrence (HR = 2.07, 95% CI 1.46-2.94) and mortality (HR = 2.17, 95% CI 1.45-3.26). MVI-positive cases also demonstrated adverse recurrence patterns, characterized by higher rates of simultaneous intrahepatic and extrahepatic recurrence (17.0% vs. 11.4%) and more frequent recurrence beyond the Milan criteria (39.8% vs. 22.9%).

CONCLUSION

MVI independently predicts adverse outcomes in NBNC-HCC, associated with adverse recurrence and reduced survival. The prognostic value of MVI is independent of viral hepatitis, supporting its importance for risk stratification in this population.