Subcentimeter hypervascular nodules with typical imaging findings of hepatocellular carcinoma on gadoxetic acid-enhanced MRI: Outcomes of early treatment and watchful waiting.

OBJECTIVES: To compare treatment outcomes of subcentimeter hypervascular nodules at high risk for developing into hepatocellular carcinomas (SHNHR) between early treatment and watchful waiting until progression to overt hepatocellular carcinoma (HCC) groups.

METHODS: SHNHRs were defined as subcentimeter hypervascular nodules with the usual imaging features of HCC on gadoxetic acid-enhanced magnetic resonance imaging (MRI). Among 63 patients with 74 SHNHRs, 27 (37 SHNHRs) received early treatment (treatment of < 1 cm nodules), and 36 (37 SHNHRs) underwent watchful waiting until progression to overt HCC. Risk factor analysis was performed for recurrence-free and local recurrence-free survival.

RESULTS: Among the 36 patients who adopted watchful waiting, 33 eventually underwent treatment because their SHNHRs progressed to overt HCC. For recurrence-free survival, significant risk factors included number of previous treatments (HR, 1.181; p < 0.001), tumour number (HR, 1.943; p = 0.009), and α-feto protein level (HR, 1.005; p = 0.037) in the multivariate analyses. Treatment strategy was not a significant risk factor for recurrence-free survival. For local recurrence-free survival from the date of treatment, only treatment modality (transarterial chemoembolization) (HR, 6.879; p = 0.002) was a significant risk factor.

CONCLUSION: Recurrence-free survival was not significantly different between early treatment and watchful waiting for SHNHRs.

KEY POINTS: • Recurrence-free survival did not vary between the two treatment strategies. • Treatment modality was a significant factor for local recurrence-free survival. • Number of treatments, tumour number, and α-FP were risk factors for recurrence.