MONDAY, March 26 (HealthDay News) -- In a small and preliminary study, researchers report that they successfully froze secondary tumors in patients with incurable breast cancer.

The findings raise the prospect of a potential new treatment for metastatic tumors in individual patients, although the research is in the very early stages.

"This therapy provides a minimal rate of cancer recurrence and no major complications," study co-author Dr. Peter Littrup, director of imaging core and radiology research at the Karmanos Cancer Institute in Detroit, said in a news release from the Society of Interventional Radiology.

The study is scheduled to be presented Wednesday at the society's annual meeting in San Francisco. Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed medical journal.

"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," Littrup said. "If we can get more data that supports percutaneous cryoablation for metastatic breast cancer, it could be a huge finding."

In percutaneous cryoablation, tiny probes insert pressurized argon gas into tumors and kill them by turning them into balls of ice.

The eight patients in the study had stage 4 metastatic breast cancer, meaning their tumors had spread widely from the breast. The tumors frequently appear in organs such as the liver, lungs, bones and kidneys.

In stage 4, the disease is considered incurable.

"At this point, treatments are considered palliative -- with the intent to keep metastases at bay while hopefully providing individuals more time and improved quality of life, rather than a complete cure," Littrup said.

"Cryoablation as a targeted therapy is beneficial because it can significantly reduce discomfort and incidence of disease," Littrup said. "It's a much better option, we think, than surgery -- especially since many metastatic patients are not candidates for surgery -- and it may potentially lead to longer survival."

The eight patients in the study lived for an average of 46 months, and two survived for at least five years.

Dr. Hannah Linden, an oncology specialist and assistant professor at the University of Washington School of Medicine in Seattle, said it's too early to know whether the treatment works since it hasn't been compared to other therapies.

"Many patients with metastatic breast cancer live a long time with gentle treatments, yet other patients who have relatively resistant tumors do poorly," she said. "While the idea of freezing a tumor to prevent it from growing is feasible and exciting, it is not proven that such an approach actually 'cures' patients or provides long-term benefit."

Although similar treatments target secondary tumors, she added, they "do not address the systemic problem of metastatic cancer. So, while it seems good to 'kill' the metastasis, the cancer is still lurking."

Breast cancer is the most common cancer among women, killing nearly 370,000 people worldwide each year. Approximately 10,000 to 15,000 new cases of stage 4 breast cancer occur in the United States each year, Littrup noted.

More information

For more about breast cancer, visit the U.S. National Library of Medicine.