Validated nomogram for the prediction of disease-free survival after hepatectomy for hepatocellular carcinoma within the Milan criteria: individualizing a surveillance strategy.

OBJECTIVE: We sought to develop a nomogram for the prediction of tumor recurrence after resection of hepatocellular carcinoma (HCC) within the Milan criteria.

METHOD: Consecutive HCC patients admitted for hepatectomy between 1994 and 2014 were enrolled in this study. Patients were excluded if they had recurrent HCC or tumors beyond the Milan criteria. Patients were randomized and assigned to the derivation and validation sets in a 1:1 ratio. Independent factors for disease-free survival were identified using the Cox regression model. A nomogram was derived and validated with the receiver-operating characteristic (ROC) and calibration curves.

RESULTS: There were 617 eligible patients included in the analysis. The median age was 59 years, 481 were male, and 87.8% of the patients were hepatitis B virus carriers. The median follow-up was 68.7 months. The 5-year overall survival rate was 73.3% and HCC recurrence was detected in 55% of the patients. In the derivation set, a nomogram was constructed based on the seven independent factors for disease-free survival: age, alpha-fetoprotein, preoperative prothrombin time, magnitude of hepatectomy, postoperative complication, number of tumor nodules, and presence of microvascular invasion. A satisfactory discrimination ability was observed in both the derivation and validation sets (c-stat 0.672 and 0.665, respectively). The calibration plot yielded agreement between the predicted and observed outcomes, using the derived nomogram.

CONCLUSION: A validated nomogram quantifies the risk of recurrence after hepatectomy for HCC within the Milan criteria, and assists with the planning of individual postoperative surveillance protocols.