Tumor Size Affects Efficacy of Adjuvant Transarterial Chemoembolization in Patients with Hepatocellular Carcinoma and Microvascular Invasion.

BACKGROUND: Patients with hepatocellular carcinoma (HCC) and microvascular invasion (mVI) have shown dismal postoperative prognosis; however, whether adjuvant transarterial chemoembolization (TACE) can improve their outcomes remains unclear.
MATERIALS AND METHODS: We retrospectively identified 549 eligible patients to form the crude cohort and adopted propensity score matching method to assemble another cohort of 444 patients with similar baseline characteristics. We assessed the effects of adjuvant TACE by stratified analyses and multivariate Cox analyses in two cohorts.
RESULTS: There was significant interaction between tumor size and adjuvant TACE with respect to overall survival (OS; p = .006 for interaction). In the matched cohort, patients who received adjuvant TACE showed higher rates of 5-year OS (72.4% vs. 50.9%, p = .005) and 5-year recurrence-free survival (50.5% vs. 36.4%, p = .003) in the tumor ≤5 cm subgroup, but not in the tumor >5 cm subgroup (32.3% vs. 24.9%, p = .350 and 18.8% vs. 19.7%, p = .180). The independent protective role of adjuvant TACE on OS was observed in patients with tumor ≤5 cm (adjusted odds ratio [OR] = 0.59, 95% confidence interval [CI] 0.36-0.97) but not in patients with tumor >5 cm (adjusted OR = 1.17, 95% CI 0.84-1.62). The effects of adjuvant TACE did not change materially while the analysis was performed in the crude cohort.
CONCLUSION: For patients with HCC and mVI, adjuvant TACE was associated with improved outcomes, but not for those with tumor >5 cm, according to the current protocol. IMPLICATIONS FOR PRACTICE: The outcomes of patients with hepatocellular carcinoma and microvascular invasion who received adjuvant transarterial chemoembolization were inconsistent in this study. According to the current protocol, adjuvant transarterial chemoembolization was associated with improved prognosis in patients with microvascular invasion, except for those with tumor >5 cm. Multivariate Cox models confirmed adjuvant transarterial chemoembolization was an independent protective factor in the tumor ≤5 cm subgroup but not in the tumor >5 cm subgroup. © AlphaMed Press 2018.