Cryoablation shows early indications of effectiveness in treating women with low-risk breast cancers, according to research presented at the annual meeting of the Radiological Society of North America (RSNA; 25–30 November, Chicago, USA). Researchers said that over the four years of the study, there has only been one case of cancer recurrence out of 180 patients.
“If the positive preliminary findings are maintained as the patients enrolled in the study continue to be monitored, that will serve as a strong indication of the promise of cryotherapy as an alternative treatment for a specific group of breast cancer patients,” said study lead author Kenneth R Tomkovich, radiologist at Princeton Radiology and director of Breast Imaging and Interventions at CentraState Medical Center in Freehold, USA.
While cryoablation has been used to treat cancers in the kidneys and lungs, it has yet to become an established treatment for breast cancer. Tomkovich began studying it for that indication more than 10 years ago, as imaging advances in mammography and ultrasound and the development of tomosynthesis enabled the detection of more low-risk cancers. These small, early-stage cancers have the potential to become invasive and life-threatening without treatment. But treatment options have not kept pace with imaging advances.
“We are finding smaller and smaller breast cancers, but we are still treating them the same way we did 30 years ago,” Tomkovich said.
Cryoablation represents a potential new weapon in the arsenal against breast cancer. The tumour-killing procedure takes less than an hour, and patients are able to return to their normal activities shortly thereafter.
As part of the Ice 3 Trial, Tomkovich and colleagues at 18 centres across the USA have been studying cryoablation as a primary treatment for breast cancer without surgical lumpectomy. Starting in 2014, the researchers began performing cryoablation on women ages 60 and over with biopsy-proven, low-risk breast cancer. The patients undergo the procedure and then are followed for recurrence with mammography at six and 12 months and then annually for five years.
As of now, the researchers have three-year follow-up data on about 20 patients and two-year follow-up data on more than 75 patients. The preliminary results have been very promising. The procedure was successfully completed in all patients, and no serious adverse events have been reported. Only one patient experienced a recurrence, giving the procedure a 99.4% success rate so far.
“Lumpectomy is 90–95% effective at removing cancer,” Tomkovich said. “We were going for something close to that, but our preliminary results have been even better. We are getting the same results at 18 centres around the country.”
Advocates claim that cryoablation has advantages over thermal ablation techniques, which use heat to destroy tumours. Additionally, there is preliminary evidence from studies on mice that cryoablation can stimulate an immune system response against cancer cells in the body.
Final results of the study will be published when five-year follow-up data is available for all the women who were treated.
“If it is proven that cryoablation works, then some women might be more inclined to opt for it over surgery,” Tomkovich said.
Kenneth Tomkovich is a consultant for Scion Medical Technologies, and is on the Scientific Advisory Board for IceCure Medical.