Breast cancer cryoablation, which destroys tumor cells by exposing them to subfreezing temperatures, appears to be an effective alternative to surgery for women aged >60 years with low-risk, early-stage breast cancer, according to interim results from the ICE3 trial. Interim results from this trial were presented by lead investigator Richard E. Fine, MD, FACS, Breast Surgeon, West Cancer Center & Research Institute, Germantown, TN, during the American Society of Breast Surgeons 22nd Annual Meeting.
In cryoablation, precise tumor engulfment producing an ice ball measuring approximately 3.5 cm to 4 cm that destroys cancerous cells is achieved through a 20- to 40-minute freeze-thaw-freeze treatment cycle using a needle-like nitrogen-chilled probe inserted directly into the tumor with ultrasound guidance. The office-based procedure, which is routinely used for various types of cancer, is performed under local anesthesia.
“The noninvasive procedure is fast, painless and can be delivered under local anesthesia in a doctor’s office,” Dr Fine explained.
The ICE3 trial, which is the largest controlled liquid nitrogen–based cryoablation trial of early-stage, low-risk breast cancer without subsequent tumor excision, enrolled and treated 194 patients aged >60 years (mean age, 75 years) with low-risk, early-stage breast cancer tumors measuring ≤1.5 cm. The duration of the cryoablation treatment ranged from 20 to 40 minutes depending on the location and size of the tumor. At the discretion of their treating physician, along with cryoablation, 27 patients received adjuvant radiation, 148 received endocrine therapy, and 1 received chemotherapy. The decision to perform sentinel lymph node biopsy was also left to the discretion of the treating physician.
Follow-up every 6 months from 6 to 60 months included mammography and optional magnetic resonance imaging. The ICE3 trial’s primary end point was disease recurrence in the ipsilateral breast at 5 years.
At a mean of 34.83 months following treatment, only 2.06% (4 patients) experienced cancer recurrence. Among patients who underwent sentinel lymph node biopsies, 2 of 15 had a positive sentinel node (1 with chronic lymphocytic leukemia and 1 with adenocarcinoma, consistent with primary breast cancer and without recurrence at 60-month follow-up). The 36-month failure-free probability rate was 99.22% (95% confidence interval, 94.58%-99.89%). Minor adverse events included bruising, localized edema, minor skin freeze burn, rash, minor bleeding from needle insertion, minor local hematoma, skin induration, minor infection, and pruritus. During follow-up visits, 95% of patients and 98% of physicians reported satisfaction with the cosmetic results.
“Recovery time is minimal and cosmetic outcomes are excellent with little loss of breast tissue and no scarring,” Dr Fine noted. ICE3 results, he added, underscore the efficacy and safety of the procedure for this population. “Cryoablation potentially represents a dramatic improvement in care for appropriate low-risk patients, and at 3 years posttreatment, the ICE3 results are extremely positive.”
Confirming cryoablation as a viable alternative to surgical excision in patients with breast cancer will require further study within a clinical trial or registry, Dr Fine concluded.