ESM-1 expression in stromal cells is predictive of recurrence after radiofrequency ablation in early hepatocellular carcinoma

Background & aims: The prognosis of hepatocellular carcinoma (HCC) treated by radiofrequency ablation (RFA) is mainly linked to tumor recurrence. So far, no tissue biomarker of recurrence has been validated in biopsy samples. We aimed at investigating the prognostic value of tissue biomarkers in HCC biopsy samples of patients treated with RFA.

Methods: All consecutive naive patients from 3 university hospitals, with compensated cirrhosis, early-stage (BCLC 0/A) uninodular HCC treated with RFA, and available tumor biopsy, were included. Edmondson's grade, and the expression of cytokeratin 19, glutamine synthase, beta-catenin, epithelial cell adhesion molecule (EpCAM), and endothelial cell-specific molecule 1 (ESM-1) were assessed. Main clinical end points were overall and early recurrence. Statistical analyses were performed using Kaplan Meier, Log-rank test, and Cox models.

Results: 150 patients were included. Recurrence, death or liver transplantation occurred in 85, 51, and 12 patients, respectively. Median follow-up was 27months. ESM-1 expression by HCC stromal endothelial cells was observed in 58 patients (40%) and was associated with higher serum AFP levels, larger tumor, and more frequent expression of EpCAM and surrogate markers of activation of the Wnt-ß-catenin pathway. The 2 independent predictive factors of overall recurrence were serum AFP (HR 1.11 [1.002; 1.22], p=0.045) and ESM-1 expression (HR 1.56 [1.004; 2.43], p=0.048). ESM-1 expression was also an independent predictive factor of early recurrence (HR 1.81 [1.02; 3.21], p=0.042).

Conclusions: ESM-1 expression by stromal endothelial cells, in tumor biopsy samples, has an independent predictive value of early recurrence after RFA.