Neoadjuvant radiotherapy to improve overall survival in resectable hepatocellular carcinoma.

e16178 Background: There is little evidence for the association between neoadjuvant radiotherapy (NRT) and improved overall survival (OS) in patients with resectable hepatocellular carcinomas (HCCs). This study aimed to determine whether NRT provides a survival benefit in these patients. Methods: We enrolled patients with resected HCC identified in the Surveillance, Epidemiology, and End Results database (2004–2015). Multiple imputation plus inverse probability of treatment weighting (IPTW) reduced selection bias. IPTW-adjusted Kaplan-Meier curves and IPTW-adjusted Cox proportional hazards models compared OS between different treatment groups. Sensitivity analyses tested the robustness of the estimates. Subgroup analysis identified the patients who could benefit most from NRT. Results: We enrolled a total of 11920 patients diagnosed between 2004 and 2015 in the study. Of these, 134 patients underwent NRT, the others underwent surgery alone (SA). The median OS in NRT was not approached, whereas in SA it was 52.0 (interquartile range, 34.25, 100.75) months. The 5-year IPTW-adjusted rates of OS in NRT versus SA were 65.3% and 46.6%, respectively. In IPTW-adjusted Cox proportional hazards regression analysis, NRT was associated with a significant OS benefit (hazard ratio [HR], 0.549; 95% confidence interval [CI], 0.327-0.921; p = 0.023). The results were robust in sensitivity analysis (E-value 2.39). Subgroup analysis demonstrated improved OS in the NRT cohort among younger patients (HR, 0.46; 95% CI, 0.26-0.83), N0 status (HR, 0.51; 95% CI, 0.28-0.94), and alpha-fetoprotein (AFP)-positive patients (HR, 0.28; 95% CI, 0.12-0.65). Conclusions: Patients with resectable HCCs may derive a survival benefit from NRT. Younger age ( < 65 years) with a positive AFP level at N0 status could be indicators for NRT. These findings enlighten current guidelines to consider NRT in patients with resectable HCCs. The present study establishes a reasonable basis for further prospective studies.