A multicenter randomized controlled trial to evaluate the efficacy of surgery versus radiofrequency ablation for small hepatocellular carcinoma (SURF trial): Analysis of overall survival.

4093 Background: The initial report of the multicenter SURF trial (surgery vs. radiofrequency ablation [RFA] for small hepatocellular carcinoma [HCC]) showed that recurrence-free survival (RFS) did not differ significantly between patients undergoing surgery and RFA. The focus of the present report was to assess the effect on overall survival (OS). Methods: The SURF trial was a multicenter, open-label, randomized, controlled, phase 3 trial conducted in 49 institutions in Japan. Patients (aged between 29 and 79 years) with Child-Pugh scores ≤ 7, largest HCC diameter ≤ 3 cm, and ≤ 3 HCC nodules were considered eligible. Before enrollment, both liver surgeons and hepatologists who perform RFA confirm that all the patients can be treated using both surgery and RFA. Patients were then randomly assigned in a 1:1 ratio to undergo surgery or RFA, stratified by age, hepatitis-C virus infection, numbers of HCC, largest HCC diameter, and institution. The co-primary endpoints were RFS and OS. As per the protocol, RFS was reported previously at 3 years after the last accrual of patients. OS was planned at 5 years after the last accrual. This trial is registered in UMIN000001795. Results: During 2009–2015, 308 patients were enrolled. After excluding ineligible patients, the surgery and RFA groups included 150 and 152 patients, respectively. Baseline factors did not differ significantly between the groups. In both groups, 90% of patients had solitary HCC. The median largest HCC diameter was 1.8 cm (interquartile range, 1.5–2.2 cm) in the surgery group and 1.8 cm (interquartile range, 1.5–2.3 cm) in the RFA group. The median (range) follow-up period was 6.4 (0.4–10.8) years in the surgery group and 6.6 (0–10.7) years in the RFA group. OS did not differ significantly between the surgery and RFA groups as the 5-year OS (95% confidence interval [CI]) was 74.6% (66.5%–81.0%) in the surgery group and 70.4% (62.2%–77.3%) in the RFA group (hazard ratio (HR), 0.96; 95% CI, 0.64–1.43; P= 0.828). The analysis after long-term follow-up in the current report showed that RFS was not significantly different between the surgery and RFA groups: the 5-year RFS (95% CI), 54.7% (46.0%–62.5%) vs. 50.5% (42.1%–58.3%); HR 0.90; 95% CI 0.67–1.22; P= 0.498. Conclusions: SURF trial revealed that OS and RFS were not significantly different between patients undergoing surgery and RFA for small HCC (≤ 3 cm and 3 nodules). Clinical trial information: 000001795.