Whether cryosurgery or cryoablation will prove a viable alternative to lumpectomy — the standard of care for women with early breast cancer — remains uncertain.
A recently completed study by the American College of Surgeons Oncology Group (ACOSOG) found promising results in 86 patients with breast cancer treated with cryosurgery, but called for further evaluation.1
No phase 3 trial is, however, planned.
“When the trial closed, there was not enough funding to establish a national randomized trial,” said Dennis Holmes, MD, a breast cancer surgeon and interim director of both the Margie Peterson Breast Cancer Center at Providence St John’s Health Center and the John Wayne Cancer Center in California. “So, I decided to take it on.”
Dr Holmes is the principal investigator for a new trial — FROST (ClinicalTrials.gov Identifier: NCT01992250).2 The sponsor, Sanarus Technologies, based in Pleasanton, California, makes the cryoablation device, the Visica 2 Treatment System, which will be used at 20 participating US sites. The system is cleared by US Food and Drug Administration (FDA) for the ablation or destruction of both cancerous and benign tumors.3
Like the earlier ACOSOG trial, FROST, will not be randomized, but contains 2 study arms. One arm will enroll women ages 70 and older whose breast cancers, by virtue of age, are generally considered indolent enough to avoid follow-up radiation or sentinel node biopsy.
Dr Holmes added that the other arm will be women aged 50 to 69 years who will be required to have follow-up radiation to reduce the risk of recurrence. But lymph node surgery will be optional in the younger cohort, as will chemotherapy, if the nodes show further cancer.
Each participant will receive 5 years of hormonal therapy following cryosurgery for control of systemic disease. Maximum tumor size at time of diagnosis is 1.5 centimeters or less. Each participant will be clinically node negative, estrogen receptor–positive, and HER2-neu negative at enrollment — “excellent candidates” for minimally invasive cryosurgery, according to Dr Holmes.
“Many patients with breast cancer have relatively non-aggressive disease, but are overtreated,” especially older women, Dr Holmes said. “The solution is to have a treatment option that provides a solution with very little morbidity,” as well as cosmetic appeal.
Cryosurgery involves circulating liquid nitrogen or argon gas through 1 or more hollow-tipped probes to target the tumor of interest, icing it in a ball of crystals. Physicians use ultrasound or MRI to guide the probe and to monitor freezing to minimize damage to nearby healthy cells. Once the frozen tissue thaws, it may be naturally absorbed by the body, or in the case of external tumors, scab over as the tissue dissolves.4
The advantage of cryosurgery include that it can be done on an outpatient basis, it’s cheaper than lumpectomy, and the incision is tiny — less than 3 millimeters across, preserving the shape of the breast, said Geetika Klevos, MD, chief of interventional oncology at the University of Miami Sylvester Cancer Center in Florida. “We don’t even have to suture the breast afterwards,” she said.
Dr Klevos has no connection to Sanarus, but became interested in cryosurgery for early breast cancer after using it for several years to treat fibroadenomas. The ideal candidates are elderly women unable to withstand surgery due to other health problems, she said, or patients concerned about the breast’s cosmetic appearance, who “still want their cancer treated adequately.”