Radiofrequency ablation is as effective as resection for treatment of both hepatocellular carcinoma and metastatic colorectal tumors in the liver, according to two studies presented Monday at the joint RSNA/SIR Foundation Interventional Oncology Symposium. The key factor in both cases was RFA's ability to easily repeat treatment on recurring tumors in a much less destructive fashion than surgery.
Three-year survival rates for patients with HCC who were treated with RFA were virtually identical to those treated with resection in a study presented by Professor Riccardo Lencioni of the Universita di Pisa.
A hepatocellular carcinoma treated with RFA.
Lencioni and his team compared 38 resections with 124 RFA treatments for patients with single lesions of 5 cm or less. The case-controlled investigation of overall survival rates, tumor progression, and tumor recurrence found a three-year survival rate of 72% for patients treated with RFA versus 65% for those treated with resection. The difference is not statistically significant.
Patients treated with RFA experienced a 19% rate of local tumor progression, while those treated with resection saw no local tumor progression. Lencioni attributed some of the recurrence to tumors that had not been fully ablated on the first treatment. However, about 50% of both RFA and resection patients experienced tumor recurrence at the three-year mark.
"The long-term survival is the result of a series of treatments," Lencioni said. "A minimally invasive approach is the key because you don't deteriorate the liver function. With surgery, you have the best possible outcome in terms of local control, but the price is high."
Similarly, three- and five-year survival rates for patients whose small, solitary colorectal metastases were treated with RFA are competitive with survival rates from resection, according to a study presented by Dr. Alice Gillams of the University College London. These findings contradict studies in the surgical literature that suggest four-year survival rates for patients treated with RFA were as low as 22%.
In Gillams' study of 35 patients treated with RFA, three- and five-year survival rates from the time of first ablation were 65% and 43%, respectively. About 40% of patients developed new metastases in the liver, which is consistent with the tumor biology of colorectal cancer. New extrahepatic disease occurred in 41% of patients, and 38% of patients experienced local recurrence. A quarter of patients are tumor-free.
"Even in the best possible surgical hands, when they take all the tumor and it's a perfect resection, the recurrence rate is phenomenally high, 40% to 70%," Gillams said. "The most important thing to do with these patients is to have really good follow-up and keep treating aggressively at each point."