Radiofrequency ablation—a minimally invasive procedure normally used to treat liver cancer—could also be used in lung cancer patients according to a study to be published in The Lancet Oncology. Randomised controlled trials are now required to investigate this promising strategy.

Lung cancer is the leading cause of cancer death in both men and women. Non-small-cell lung cancer (NSCLC) constitutes about 80% of primary malignant tumours in the lung. While surgery is currently the standard of care for early-stage NSCLC, it is not suitable for all patients. Factors such as the pulmonary reserve associated disease and the medical fitness of patients for surgery all need to be considered. The lungs are also the second most frequent site of metastatic disease. Again, surgery is frequently used in these patients and has survival benefits especially when the type of tumour favours surgery, for example when it has spread from the colon. But again the factors above can make a patient unsuitable for surgery.

Patients rejected for surgery are currently offered radiotherapy or chemotherapy protocols, however long-term outcomes are not fully satisfactory. Some patients have such poor lung function that radiotherapy is also unsuitable.

Percutaneous image-guided radiofrequency ablation (RFA) is a minimally invasive technique used to treat solid tumours. Currently optimised RFA technology produces large volumes of tumour death in a controlled fashion, and has become a viable therapeutic option for treatment of liver cancer where surgery is unsuitable. RFA is also much easier on the patient compared with surgery: RFA focuses only on the target tumour and is usually carried out in less than one hour, with a very short hospital stay. And lung function tests have shown that RFA has no negative effect on non-tumoral lung tissue and does not negatively affect patients’ quality of life. Professor Riccardo Lencioni, Division of Diagnostic and Interventional Radiology, Cisanello University Hospital, Pisa, Italy and colleagues did the RAPTURE study—a prospective multicentre trial—to test the feasibility safety and efficacy of RFA in treating malignant lung tumours.

A series of 106 patients, with 183 malignant lung tumours that were 3.5 cm in diameter or smaller, were enrolled in the study with proof of malignancy obtained by biopsy in all patients. NSCLC was diagnosed in 33 patients metastatic lung cancer from the colon in 53 and metastatic lung cancer from other sites in the body in 20. All patients were rejected for surgery and were considered unfit for radiotherapy or chemotherapy. Patients underwent RFA and were followed for up to two years.

The researchers found that a confirmed complete response of tumours lasting at least one year was found in 75 of 85 assessable patients (88%). Overall survival was 70% at 1 year and 48% at 2 years in patients with NSCLC and 89% at 1 year and 66% at 2 years in patients with lung metastases from colon cancer. Cancer-specific survival was 92% at 1 year and 73% at 2 years in patients with NSCLC and 91% at 1 year and 68% at 2 years in patients with lung metastases from colon cancer. The 13 patients with stage I NSCLC had a 2-year overall survival of 75% and a 2-year cancer-specific survival of 92%. Furthermore the ablation device was correctly placed in 99% of the patients and no procedure-related deaths occurred in any of the 137 ablation sessions. Major complications consisted of pneumothorax (27 procedures) or pleural effusion (4) which needed drainage but there was no significant decline in lung function.

The authors say that RAPTURE is the first such trial assessing treatment of lung cancer using radiofrequency ablation. They say: “Our study shows that radiofrequency ablation can be completed successfully in high percentage of patients with small lung tumours...The safety profile of the procedure was also acceptable with no mortality or life-threatening complications associated with it...A randomised controlled trial comparing radiofrequency ablation versus standard treatment options is now warranted to prove the clinical benefit of this approach.”