Assessment of Preoperative Magnetic Resonance Imaging Staging in Patients With Hepatocellular Carcinoma Undergoing Resection Compared With the Seventh American Joint Committee on Cancer System

Objectives: The aim of this study was to compare the prognostic utility of a staging system using magnetic resonance imaging (MRI) with the seventh American Joint Committee on Cancer (AJCC) staging system in patients with hepatocellular carcinoma (HCC) who underwent hepatic resection. Materials and Methods: A total of 175 consecutive patients with HCC who underwent curative hepatic resection after MRI between January 2000 and December 2007 were analyzed. In lieu of microvascular invasion, which is used by the AJCC staging system, we devised an MRI staging system in which a size criterion of 2 cm was used to differentiate between tumor stages 1 and 2. All patients were retrospectively staged using the seventh AJCC staging system and the preoperative MRI staging system. Differences in disease-free and overall survival rates between different stages by the MRI and AJCC staging systems were analyzed using the Kaplan-Meier method with log-rank testing. The predictive accuracy of the 2 staging systems was directly compared using the time-dependent receiver operating characteristic curve analysis. Results: Median follow-up period was 222.9 weeks. During the follow-up period, 74 (42.3%) patients experienced tumor recurrence and 22 (12.6%) died. The median disease-free survival and overall survival were 131.1 and 222.9 weeks, respectively. Both staging systems were excellent for the prediction of disease-free survival across different tumor stages but failed to predict overall survival differences between stages 1 and 2. For disease-free and overall survivals, the time-dependent receiver operating characteristic curve analysis revealed no significant differences in predictive accuracy between the 2 staging systems. Conclusion: A preoperative MRI staging system using a size threshold instead of microvascular invasion may predict the prognosis of HCC patients undergoing hepatic resection as accurately as the seventh AJCC tumor-node-metastasis staging system.