Radiofrequency Ablation for Liver Mets Improved Survival in CRC

Treating patients with unresectable colorectal cancer liver metastases with targeted treatment using radiofrequency ablation and systemic chemotherapy resulted in an improved long-term overall survival compared with the use of chemotherapy alone, according to the 10-year overall survival results of the phase II EORTC-NCRI-CCSG-ALM Intergroup 40004 (CLOCC) study (abstract 3501), presented at the 2015 American Society of Clinical Oncology (ASCO) Annual Meeting held May 29 to June 2 in Chicago.

“Despite the limitations in this trial due to reduced sample size, this encourages the use of ablative techniques as a treatment modality in patients with unresectable colorectal liver metastases,” said presenter Theo Ruers, MD, PhD, of the Netherlands Cancer Institute. “In these patients, complete treatment of all liver metastases should be aimed for, which should be discussed by a multidisciplinary team.”

As background, Ruers said that although radiofrequency ablation is increasingly used in patients with unresectable colorectal liver metastases, prospective data backing this method in a defined therapeutic setting have been scarce.

This trial included 119 patients randomly assigned to chemotherapy alone (n = 59) or radiofrequency ablation plus chemotherapy (n = 60). The chemotherapy regimen used in the study was 6 months of FOLFOX, with bevacizumab later added. Patients could undergo resection when chemotherapy converted unresectable disease to resectable disease. The primary endpoint of the study was 30-month overall survival of greater than 38% for the combined treatment group.

At a median follow-up of 4.4 months, the 30-month overall survival rate for combined treatment was 61.7% compared with 57.6% in the systemic chemotherapy arm. There was also a significant improvement in progression-free survival, with a median survival of 16.8 months in the combined arm compared with 9.9 months in the chemotherapy-alone arm (P = .025).

The updated results were presented after a median follow-up of 9.7 years. At this time, the median progression-free survival was 16.82 months for the combined arm compared with 9.92 months for the chemotherapy-alone arm (hazard ratio [HR] = 0.57; 95% confidence interval [CI], 0.38–0.85; P = .005). The median overall survival was 45.6 months for the combined arm compared with 40.54 months for the chemotherapy arm (HR = 0.58; 95% CI, 0.38–0.88; P = .010).

“The current overall survival status shows that 35% of patients were still alive at last contact in the radiofrequency arm vs 10% in the systemic arm and almost all patients, when they died, died of progressive disease, and hardly any other causes of death were noted in both arms,” Ruers said.

Commenting on these long-term results, discussant Ricky A. Sharma, MA, MB, of Gray Institute for Radiation Oncology and Biology at the University of Oxford, said, “We should rethink the way that patients…are followed up purely by doctors doing chemotherapy and systemic therapy, because at multiple points in that patient’s pathway it is feasible that they could benefit from surgery plus or minus thermal ablation.”