An experimental therapy that freezes deep tumours offers new hope to women with advanced breast cancer, early findings suggest.
The treatment could be used as a last line of defence to halt cancer that is spreading round the body, say scientists.
Currently, women with "metastatic", or spreading, breast cancer are said to be incurable.
Their treatment consists of managing and holding back the disease for as long as possible. This may involve harsh forms of chemotherapy with damaging side effects.
The new treatment involves locating tumour "hotspots" in organs such as the liver and lungs, and using an ice probe to wipe them out.
The fine probe is inserted through the skin and guided to the site of the tumour using ultrasound or a CT scan.
Pressurised argon gas is then forced into the tumour, turning it into a ball of ice and killing the cancerous cells.
A major advantage of the "percutaneous cryoablation" technique is that it causes minimal damage to surrounding healthy tissue.
Eight breast cancer patients with nine secondary tumours in the liver, lung and kidney took part in a preliminary test of the therapy.
US scientists presenting the results at a meeting of the Society of Interventional Radiology in San Francisco, California, said all procedures were considered "successful".
All individual tumours remaining in the body were found and there was little cancer recurrence.
Participants typically survived 46 months and a quarter were still alive more than five years after treatment.
Lead researcher Dr Peter Littrup, from the Karmanos Cancer Institute in Detroit, US, said: "Why should people have to keep changing from one expensive chemo drug to another when there are just a few remaining spots? Cryoablation could offer these individuals a new treatment option.
"This therapy provides a minimal rate of cancer recurrence and no major complications, making these ice balls ideal for targeting metastatic tumours that are limited in number and location.
"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."