When surgical procedures are not an option, radiofrequency (RF) ablation can be an effective treatment of colorectal lung metastases, resulting in a 5-year survival rate for more than 51%, of subjects in a recent study, published in the Journal of Vascular and Interventional Radiology.

Yusuke Matsui, MD, and co-authors pointed out that RF ablation is not necessarily the first treatment physicians should consider for colorectal lung metastases.

“Pulmonary metastasectomy is believed to prolong survival and therefore is recommended as a first-line treatment when possible,” Matsui et al wrote. “However, patients with pulmonary metastases are often not surgical candidates because of the multifocal nature of the disease, various comorbidities, or refusal to undergo surgery.”

In those instances where surgery is not an option for the patient, the authors believe RF ablation should be considered. “Compared with surgical metastasectomy, the advantages of RF ablation include its minimal invasiveness, repeatability, and minimal influence on pulmonary function,” Matsui et al wrote.

For the study, 84 patients with colorectal cancer with pulmonary metastases were treated with lung RF ablation from June 2001 to December 2012. All patients had medically inoperable disease or refused surgery. The patients’ primary lesions were colon cancer in 49 instances, and rectal cancer in 35. Two types of electrodes—a multitined expandable electrode and a single internally cooled electrode—were used in the study.

The overall survival rates were 95.2% after one year, 65% after three years and 51.6% after five years. In addition, there was local tumor progression in 24 (14%) of the 172 metastases. The rate of technique effectiveness for all tumors was 88.3% after one year. It was then 84.1% after three years, and 82.1% after five years.

A total of 36 patients died during follow-up of the treatment, 29 as a result of the colorectal cancer’s progression, and the remaining seven deaths were from other or unknown causes. Side effects such as pneumothorax were observed after some of the RF ablation treatments, but there were just two instances of grade 3 adverse events: one instance each of pneumonitis and pleural infection.

“In conclusion, this retrospective study indicates that RF ablation of colorectal lung metastases was minimally invasive and provided favorable long-term survival despite occasional local failure,” the authors wrote.

A second phase of this study is presently underway.