Prognostic Nomograms Based on Microvascular Invasion Grade for Early-stage Hepatocellular Carcinoma Patients After Curative Hepatectomy

Background: This is the first study to develop and evaluate a predictive model based on the microvascular invasion (MVI) classification for early recurrence and survival after curative hepatectomy in patients with early-stage hepatocellular carcinoma (HCC).Methods: The database of patients with early-stage HCC who underwent curative hepatectomy in the First Affiliated Hospital of Fujian Medical University and the First Affiliated Hospital of Xiamen University were retrospectively reviewed. Kaplan-Meier curves and Cox proportional hazards regression models were used to analyze disease-free survival (DFS) and overall survival (OS). Nomogram models were constructed on the datasets from the First Affiliated Hospital of Fujian Medical University and the datasets were validated using bootstrap resampling with 30% samples as internal validation. Data of patients from First Affiliated Hospital of Xiamen University were used for external validation.Results: A total of 703 patients with early-stage HCC were included in our study. An eight-factor nomogram for predicting recurrence or metastasis and a six-factor for predicting survival were created. The concordance indexes (C-index) were 0.775 (95% confidence interval [CI], 0.720-0.830) for the DFS nomogram and 0.812 for the OS nomogram (95% CI, 0.732-0.892), respectively, in the training cohort, and 0.865 (95% CI, 0.806-0.924) and 0.839 (95% CI, 0.675-1.00), respectively, in the internal validation cohort, and 0.857 (95% CI, 0.763-0.951) and 0.842 (95% CI, 0.708-0.970), respectively, in the external validation cohort. The calibration curves showed optimal agreement between the predicted and observed DFS and OS rates. The predictive accuracy was significantly better than that of the classic HCC staging systems.Conclusions: This study developed and validated nomograms for predicting recurrence, especially early recurrence, and overall survival in early-stage HCC patients after curative resection with high predictive accuracy.