Minimizing complications with radiofrequency ablation for liver cancer - The importance of properly controlled clinical trials and standardized reporting

Surgical resection has long been considered to be the only treatment to offer prolonged survival to patients with primary or metastatic cancer confined to the liver. Unfortunately, most of patients with hepatic malignancy have disease that is not amenable to surgical resection because of large tumor size, multifocal disease, inadequate predicted liver reserve, or comorbid medical conditions precluding safe operation. These facts led to the recent development of multiple nonresectional modalities for ablating liver tumors, one of which is radiofrequency ablation (RFA).(1) When used properly in appropriately selected patients, it is hoped that RFA will improve survival for some patients with hepatic cancer who cannot undergo liver resection. The safety profile of RFA for liver tumors was initially established through uncontrolled series of heterogenous groups of patients treated with various techniques; overall complication rates appear to be less than 10% and procedure-related mortality is less than 1% in experienced hands.(1,2) This safety profile led the Food and Drug Administration to approve RFA devices for clinical use in The United States. It is important to note, however, that this approval was granted for the ability to destroy tissue and not for the ability to completely destroy or cure cancer. There has been no controlled prospective clinical trial published demonstrating that RFA extends the survival of patients with any type of cancer of the liver.(2) In addition, a recent technology assessment on RFA for the treatment of liver cancer emphasized the substandard quality of data on the subject.(2) Despite these issues, aggressive marketing programs by the manufacturers of RFA devices led to the rapid diffusion and worldwide use of RFA for metastatic and primary liver cancer. Even more concerning is the fact that RFA is widely perceived as a safe and "minimally invasive" treatment modality for unresectable liver cancer although a clear understanding of its limitations and risks are not clearly delineated. Strasberg and Ludbrook recently published an eye-opening and insightful work in which they discussed the need for regulatory oversight to monitor the implementation of new surgical technologies and innovative practice.(3) They argued that the clinical use of new technologies, such as RFA for the ablation of liver cancer, whose clinical efficacy or risks are not yet thoroughly assessed,(2) be restricted to clinical trials so that patient safety is monitored under the purview of human subjects research. Unfortunately, few studies exploring the utility of RFA for ablating liver cancers have been carried out and published under the auspices of a closely monitored clinical trial.