Radiofrequency ablation to destroy small liver metastases from primary colorectal cancer increases survival rates

This paper looks at the long term survival rates after radiofrequency ablation treatment of small metastatic liver tumors in patients with primary colorectal cancer.  

Radiofrequency tumour ablation is a method used to treat patients whose tumors cannot be treated surgically.  The method involves guiding needles using imaging methods such as ultrasound or CT scans to the site of the tumor.  The tumor is then treated with a high intensity radiowave which heats up the cancerous tissue and destroys it.  Lung and liver metastases are the tumours most likely to be untreatable with surgery. In patients where metastatic tumors are left untreated, the percentage that survive for a further five years is only 5%.  This technique of treatment therefore offers a ray of hope with good outcomes to those patients who may otherwise be treated only with chemotherapy.   

This paper looks at the use of radiofrequency ablation to treat 99 patients with a total of 202 small metastatic tumors of the liver.  All patients had primary colorectal cancer and the tumors were 0.8 to 4.0cm.  Following this ablation treatment, patients returned for scans to identify if the tumors had reoccurred.  The study looked at the number of tumors that progressed following the procedure and long term survival rates of the 99 patients included in this study.

Results showed that 24 (11.8%) of the 202 treated tumors progressed following ablation.  13 of these 24 were retreated and these patients had a longer survival time than those who were not retreated. At follow up appointments a total of 125 new liver metastases were found, again a number of these (41) were retreated with ablation therapy.  The survival rate at 1 year was 98%, this then decreased to 69.3%, 47.8%, 25.0% and 18.0% at 3, 5, 7 and 10 years after treatment.

Overall, when compared to a 5% survival rate at 5 years in patients who do not receive treatment for metastatic tumors, these results are very encouraging. 47.8% is a massive increase from 5% and is a positive step forward in treatments available to patients. 19 of the patients treated in this study had refused to have surgery to remove the metastatic liver tumours.  These positive results may make this more of an option to patients who do not want to undergo extensive surgery. 

While very encouraging, these results have to be considered in a broader context. The number of patients in this study was small and the procedure is still not widely available. Doctors also need special training in order to perform these new procedures. Further studies are awaited to confirm the results and determine the role of radiofrequency ablation in colorectal cancer management.