Three-dimensional MR elastography-based stiffness for assessing the status of Ki67 proliferation index and Cytokeratin-19 in hepatocellular carcinoma.

Objectives: To investigate the potential diagnostic value of MR elastography (MRE)-based stiffness to noninvasively predict the status of Ki67 proliferation index (PI) and Cytokeratin-19 (CK19) in hepatocellular carcinoma (HCC).

Methods: Two hundred and nineteen patients with histologically proven HCCs (high/low Ki67 PI, N = 134/85; +/-CK19, N = 47/172) who underwent preoperative MRI and MRE examinations were retrospectively enrolled. Imaging features and clinical information were analyzed to develop the clinical-radiologic models. Logistic regression and area under the receiver operating characteristic curve (AUC) analyses were used to evaluate the status of Ki67 PI and CK19, and their model performances.

Results: Tumor stiffness (TS) (p = 0.004) and TS/liver stiffness (LS) (p < 0.001) were significantly independent predictors of high Ki67 PI and positive CK19, respectively. By incorporating TS or TS/LS value, the AUCs of the clinical-radiological models have been improved for identifying high Ki67 PI from 0.796 to 0.819 (p = 0.113), and positive CK19 from 0.817 to 0.852 (p = 0.026). Patients with predicted high Ki67 PI/positive CK19 based on the combined models had worse recurrence-free survival (RFS) and overall survival (OS) than those with low Ki67 PI/negative CK19 (all p < 0.05), respectively. The combined statuses of predicted Ki67 PI and CK19 stratified patients into three distinct subgroups with significantly different RFS and OS (all p < 0.05). Notably, patients with predicted high Ki67 PI and positive CK19 had the worst prognosis.

Conclusions: Three-dimensional MRE could be a promising tool for evaluating and stratifying the prognosis of HCC patients by predicting the status of Ki67 PI and CK19 preoperatively.

Key Points: Question Can MRE-based stiffness predict Ki67 PI and Cytokeratin 19 (CK19) in HCC? Findings MRE-based stiffness is an independent predictor of high Ki67 PI and CK19-positive and improves the diagnostic performance of clinical-radiological models predicting Ki67 PI and CK19 status. Clinical relevance MRE-based stiffness is a noninvasive predictor of high Ki67 PI and CK19-positive, and in combination with clinical-radiological models can be used for prognostic analysis, which could refine patients' selection for adjuvant therapy or surveillance.