Cryoablation is promising in the treatment of low-risk breast cancers

"If the positive preliminary results are maintained as patients enrolled in the study continue to be monitored, this will serve as a strong indication of the promise of cryotherapy as an alternative treatment for a patient." specific group of patients with breast cancer, "said lead author Kenneth R. Tomkovich, MD, radiologist at Princeton Radiology and director of breast imaging and interventions at CentraState Medical Center, Freehold, NJ

Cryoablation, also known as cryotherapy, has been used to treat cancers of other body organs, including the kidneys and lungs, but has not yet been established as a treatment for breast cancer . Dr. Tomkovich began studying it for this indication over 10 years ago, while advances in mammography and ultrasound imaging and the development of tomosynthesis helped detect more low-grade cancers. risk. These small cancers at an early stage can become invasive and life-threatening without treatment. But treatment options have not kept pace with advances in imaging.

"We are discovering smaller and smaller breast cancers, but we are still treating them the same way as we did 30 years ago," said Dr. Tomkovich.

Cryoablation represents a potential new weapon in the arsenal against breast cancer. The procedure begins with the introduction of a probe into the tumor by a pea-sized incision in the skin while the patient is under local anesthesia. The probe is guided by high-definition ultrasound in conjunction with mammography images. Once the probe is in place, liquid nitrogen is introduced. During the initial eight-minute freezing cycle, an ice ball forms around the tumor, killing the cancer. After a thaw cycle, another eight-minute freeze cycle is used to ensure complete destruction of the cancer cells. The procedure takes less than an hour and patients can resume normal activities shortly thereafter.

As part of the Ice 3 trial, Dr. Tomkovich and colleagues at 18 US centers studied cryoablation as a primary breast cancer treatment without surgical lumpectomy. Starting in 2014, researchers began practicing cryoablation on women 60 years of age and older with low-risk and biopsy-proven breast cancer. Patients undergo the procedure and are then followed for a recurrence with a mammogram at six and 12 months, then once a year for five years.

Currently, researchers have three-year follow-up data on approximately 20 patients and two-year follow-up data on more than 75 patients. Preliminary results are very promising. The procedure has been successfully completed in all patients and no serious adverse events have been reported. Only one patient had a recurrence, giving the procedure a success rate of 99.4% so far.

"Lumpectomy is effective against cancer by 90 to 95%," said Dr. Tomkovich. "We wanted to get closer to that, but our preliminary results were even better, we get the same results in 18 centers across the country."

Cryoablation has advantages over ablation techniques that use heat to destroy tumors. On the one hand, the fabric retains its appearance when it is frozen, while the heating tends to distort it, making the imaging less reliable. Tomkovich likens the process to how bacon retains its shape when it is frozen, but curls up and shrinks when it is cooked. In addition, preliminary studies on mice show that cryoablation can stimulate an immune system response against cancer cells in the body.

The final results of the study will be published when five-year follow-up data will be available for all women treated.

"If it is proven that cryoablation works, then some women might be more inclined to opt for it rather than surgery," said Dr. Tomkovich.