Radiofrequency Ablation Improves Survival Over SBRT in Localized HCC

Anne M. Covey, MD

Radiofrequency ablation (RFA) was associated with superior 5-year overall survival (OS) compared with stereotactic body radiotherapy (SBRT) for patients with localized hepatocellular carcinoma, according to an observational study published in the Journal of Clinical Oncology. ¹

Investigators reviewed data collected in the National Cancer Database on 47,634 patients treated with RFA or SBRT for clinical stage I (T1N0M0) or stage II (T2N0M0) primary HCC from 2004 to 2013. Patients who underwent lobectomy, extended lobectomy, resection, hepatectomy, or liver transplantation at any time were excluded.

Overall, 3684 patients (92.6%) received RFA and 296 (7.4%) received SBRT. After propensity matching, 5-year OS was 29.8% (95% CI, 24.5-35.3) in the RFA group versus 19.3% (95% CI, 13.5-25.9) in the SBRT group (HR, 0.67; 95% CI, 0.55-0.81; P <.001). Investigators said the survival benefit of RFA was consistent across all subgroups, and was robust to the effects of severe fibrosis/cirrhosis.

“This report represents the first sizeable assessment of the comparative effectiveness of RFA versus SBRT with OS as a primary endpoint,” corresponding author Devalkumar J. Rajyaguru, MD, department of medical oncology, Gundersen Health System in Wisconsin, and colleagues wrote.

“Although our results are limited by the biases related to the retrospective study design, in the absence of a randomized clinical trial, we believe that our findings should be considered when recommending local ablative therapy for localized unresectable HCC. Rigorous prospective randomized studies are needed to accurately define the role of SBRT and optimize patient selection in this population,” added Rajyaguru et al.

Although there was no data showing that technological improvements in interventional radiology techniques have actually improved the outcomes of patients with HCC treated with RFA, these results show a clear advantage for patients treated more recently. Investigators wrote that patients treated with RFA from 2009 to 2013 had significant improvement in OS compared with those treated from 2004 to 2008.

The proportion of patients receiving SBRT increased over time, with an annual percent change of 12% (P <.001). Most patients (79.7%) received 3 to 5 fractions of treatment. Survival with SBRT remained unchanged over the study period.

Patients who received SBRT tended to be older (≥71 years), more frequently white compared to nonwhite/non-African American, and had fewer comorbid conditions. SBRT use was also more frequent in patients with larger tumors, but that did not translate into better survival for those patients.

“In our study, RFA was superior to SBRT, even if the tumor was >3 cm,” Rajyaguru et al wrote. “We believe that improved local control rates achieved with SBRT for large tumors do not necessarily translate into superior survival, and future studies should focus on more clinically relevant endpoints, such as survival when examining the comparative effectiveness among local ablative therapies.”

Patients with a low fibrosis score (0-4) or no fibrosis information recorded were more likely to undergo SBRT. Patients with fibrosis scores of 5 to 6 or severe fibrosis/cirrhosis were more likely to receive RFA as initial treatment compared with SBRT (24.6% vs 10.8%).

In an accompanying podcast, Anne M. Covey, MD, professor of radiology, Weill Cornell Medical College, said the results are generalizable because the large patient population comes from all areas of the country, a variety of treatment settings, and a range of socioeconomic strata.2

“Earlier detection due to improved screening programs will likely increase the number of patients with small tumors eligible for RFA and SBRT,” she said. “Exciting new technology in ablation, including improved assessment of treatment margins and the ability to create larger ablation zones, and in radiation oncology, including proton therapy, continue to improve the outlook for patients with hepatocellular carcinoma.”

References

1. Rajyaguru DJ, Borgert AJ, Smith AL, et al. Radiofrequency ablation versus stereotactic body radiotherapy for localized hepatocellular carcinoma in nonsurgically managed patients: Analysis of the national cancer database [published online January 12, 2018]. J Clin Oncol. doi: 10.1200/JCO.2017.75.3228.
2. Covey AM. Survival following radiofrequency ablation versus stereotactic body radiotherapy for early-stage hepatocellular carcinoma. J Clin Oncol [podcast]. doi: 10.1200/JCO.2017.75.3228.