Predictive Factors of Microvascular Invasion in Patients with Hepatocellular Carcinoma Larger Than 5 cm

BACKGROUND: Patients with hepatocellular carcinoma (HCC) who undergo liver resection and transplantation are predicted to have a poor outcome if the disease is associated with vascular invasion. This study aimed to identify preoperative predictors of microvascular invasion in patients with HCCs larger than 5 cm. METHODS: From May 1992 to October 2005, 231 patients underwent curative hepatic resection for HCC. Of these, 96 patients had HCCs larger than 5 cm. Analysis was limited to patients without macroscopic vascular invasion (n = 65). RESULTS: Multivariate analysis showed that patients with tumors larger than 7 cm and type 2 (single nodular type with extranodular growth) and type 3 (contiguous multinodular type formed by a cluster of small and contiguous nodules) tumors had an increased risk of microscopic vascular invasion. The overall incidence of microscopic vascular invasion was 46.2% (n = 30), but only 12.5% (2/16) in patients with type 1 tumors (single nodular type that is approximately round with a clear demarcation) measuring less than 7 cm. CONCLUSION: Larger tumors (>7 cm) and type 2 and type 3 tumors are strong predictors of microvascular invasion in patients with HCCs larger than 5 cm.