Percutaneous cryoablation could potentially be used as a last line of defense to halt individual spots of remaining metastatic disease by freezing and destroying tumors, according to a study presented March 28 at the Society of Interventional Radiology's (SIR) 37th annual scientific meeting in San Francisco.

Peter J. Littrup, MD, director of imaging core and radiology research at the Karmanos Cancer Institute in Detroit, described cryoablation as “the fourth leg on the stool of cancer care,” in addition to primary treatments of radiation therapy, surgery and chemotherapy.

"Stage IV metastatic breast cancer … is currently viewed as incurable and associated with a low rate of survival. While less than 5 percent of those are initially diagnosed with metastases, an estimated 25 to 40 percent will develop these additional tumors, which are notoriously difficult to wipe out, even with multiple forms and repeated rounds of treatment," said Littrup in a statement. "At this point, treatments are considered palliative.”

Littrup offered cryoablation of remaining spots as an alternative to expensive chemotherapy regimens.

Most commonly, metastatic tumors are located in the liver, the lungs and pleura. CT- or ultrasound-guided percutaneous cryoablation delivers pressurized argon gas to target and kill single tumors that persist after first and follow-up treatment. This treatment could provide a valuable alternative to other spot-therapies because there is minimal damage to surrounding healthy tissues and the side effects and recovery time are dramatically reduced when compared to those of other therapies, said Littrup.

The researcher shared results of small study of eight women with nine tumors who underwent percutaneous cryoablation for secondary tumors in the liver, lung and kidney. A mean of 1.1 ablations per patient were performed.

Six of the eight subjects had formerly undergone at least a single mastectomy prior to treatment with percutaneous cryoablation. There were no serious complications according to Common Toxicity Criteria for Adverse Events and all procedures were considered successful. All individual tumors remaining in the body were found and the local cancer did not recur.

The median overall survival from time of stage IV diagnosis was 46 months, and 25 percent survived past the five-year anniversary of treatment.

"This therapy provides a minimal rate of cancer recurrence and no major complications, making these ice balls ideal for targeting metastatic tumors that are limited in number and location," said Littrup. "This is a preliminary study, and at this point we're hoping that the evidence could be a stepping stone for a bigger study to look at more patients. If we can get more data that supports percutaneous cryoablation for metastatic breast cancer, it could be a huge finding," he added.

For more about cryoablation, please read "Proving its Worth: Interventional Oncology Squeezes and Freezes Tumors," in the March issue of Health Imaging.