Liver-directed combined radiotherapy as a bridge to curative surgery in locally advanced hepatocellular carcinoma beyond the Milan criteria

Background and purpose: Liver-directed combined radiotherapy (LDCRT) can provide substantial tumor control, which may be an effective bridge to curative surgery for selected patients. We aimed to investigate the outcomes of LDCRT for locally advanced hepatocellular carcinoma (LAHCC) beyond the Milan criteria. Materials and methods: We identified 1078 patients diagnosed with LAHCC who received LDCRT and compared the outcomes based on no surgery, conversion to surgical resection, and liver transplantation (LT). Predictive factors for conversion to curative surgery were identified using logistic regression analysis. Results: The most frequently used LDCRT strategies were concurrent chemoradiation (CCRT) (497 patients, 46.1%) and transarterial chemoembolization (TACE) plus radiotherapy (251 patients 23.3%). After LDCRT, 96 (8.9%) and 42 patients (3.9%) received surgical resection and LT, respectively. After a median follow-up of 14.4 months, the 5-year overall survival (OS) rate was 16.5% for all patients. Conversion to curative surgery group had higher 5-year OS (surgical resection vs. LT vs. no surgery: 58.1% vs. 54.3% vs. 10.2%, p < 0.001). Patients aged < 60 years with a single tumor, no treatment history, pre-treatment Child class A, lower pre-treatment tumor marker levels, and radiologic complete or partial response (all p < 0.050) had a higher chance of conversion to surgery. Conclusion: LDCRT could convert tumors to within the Milan criteria as a bridge to curative surgery, and improved long-term survival for the selected patients. Clinicians should consider LDCRT followed by curative surgery for young patients who are treatment-naïve and have good liver function with favorable tumor characteristics showing radiologic response to LDCRT.