Utility of tumor and non-tumor biopsies during percutaneous radiofrequency ablation for hepatocellular carcinoma.

BACKGROUND & AIMS: We aimed to assess the safety and diagnostic/prognostic value of tumor and non-tumor biopsies systematically collected during radiofrequency ablation (RFA) of hepatocellular carcinoma (HCC). METHODS: We prospectively included patients with a first diagnosis of HCC who underwent tumor and non-tumor biopsies during percutaneous RFA between 2015 and 2021. We analyzed the complications, percentage of diagnostic tumor biopsies, ability to perform molecular biology, and the non-tumor liver biopsy results, and correlated histology with prior non-invasive diagnosis and oncological outcomes. RESULTS: In total, 248 patients (86% male, median age 68) with 302 tumors treated by RFA and with available tumor biopsy were included. HCC was single in 78% and bifocal in 21% of patients, with a median size of 24 mm. Bleeding occurred in six cases (1.9%) without related deaths. Biopsies enabled HCC diagnosis in 66% of cases, with positivity linked to nodule size (p <0.0001), location (p = 0.04), and ultrasound visibility (p = 0.004). A discrepancy between prior tumor board and subsequent histological diagnosis was observed in 5% of cases. Among the 302 biopsies, 34% were non-diagnostic, 61% were HCC, 3% were cholangiocarcinoma (CCA)/hepatocholangiocarcinoma (cHCC-CCA), and 2% were dysplastic nodules. Survival was shorter in patients with CCA/cHCC-CCA (p <0.001). Macrotrabecular-massive HCC was associated with higher rates of global tumor recurrence (p = 0.037). More than 25% of tumor cells in paraffin-embedded samples were associated with expression of cancer genes on transcriptomic analysis of the corresponding frozen samples, assuring their usefulness for molecular analysis. In non-tumor biopsies, cirrhosis was histologically confirmed in 82% of cases, with a 15% discrepancy between diagnosis of cirrhosis at tumor board and on biopsy. CONCLUSION: Systematic tumor and non-tumor biopsy during RFA for a first diagnosis of HCC is feasible, safe, and brings valuable diagnostic, therapeutic, and prognostic data. IMPACT AND IMPLICATIONS: Tumor and non-tumor biopsies during radiofrequency ablation for hepatocellular carcinoma are both safe and feasible, with a low complication rate and no procedure-related deaths. We demonstrated the diagnostic utility of biopsies, revealing discrepancies in 5% of cases between tumor board and histological results, which could refine patient management strategies. We identified significant associations between hepatocellular carcinoma subtypes and recurrence rates, and found that molecular analysis based on frozen tumor samples is feasible in most cases and could be guided by the percentage of tumors cells on paraffin-embedded samples.