Cryoablation may be promising alternative to surgery for low-risk breast cancer
Cryoablation may be an effective primary treatment option for women with low-risk breast cancer, according to preliminary findings from the Ice 3 trial.
“If the positive preliminary findings are maintained as the 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 specific group of [patients with] breast cancer,” Kenneth R. Tomkovich, MD, radiologist at Princeton Radiology and director of breast imaging and interventions at CentraState Medical Center in Freehold, New Jersey, said in a press release.
The trial included women aged 60 years and older who underwent cryoablation across 20 centers in the U.S. for low-risk breast cancer. Researchers will use mammography to monitor the women for breast cancer recurrence at 6 months and 12 months, and then annually for 5 years.
Three-year follow-up data on nearly 20 patients, and 2-year follow-up data on more than 75 patients, showed success rate higher than 98%, with no serious adverse events reported.
HemOnc Today spoke with Tomkovich about the technique, what prompted the study and the potential clinical implications of the findings.
Question: How is this a pproach unique from the current standards of treatment for low-risk breast cancer?
Answer: The standard approach includes surgery followed by chemotherapy or radiation. This is the first trial in the world to test cryoablation instead of lumpectomy as primary treatment for low-risk breast cancer. We want to determine if cryoablation is as effective as lumpectomy.
Q: What prompted this research?
A: I have been interested in breast intervention for some time. Following the completion of my fellowship in interventional radiology, the area of ablation started to emerge. It was first tested as thermal ablation for liver cancer and other tumor types. This was followed by cryoablation for kidney cancers and lung cancers. While performing these types of procedures, I was puzzled as to why no one was using cryoablation for breast cancers. The research did not seem positive or show results anywhere near those associated with lumpectomy. I took this as a personal point of interest to develop a research protocol to try to ‘crack the code.’
Q: Can you explain how the technique works?
A: Cryoablation begins with the introduction of a probe into the tumor through 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 into it. During the initial 8-minute freeze cycle, an ice ball forms around the tumor, which treats the cancer. After a thaw cycle, another 8-minute freeze cycle is used to ensure complete treatment of the cancer cells. The procedure takes less than 1 hour, and patients are able to return to their normal activities shortly thereafter.
Q: How is the study being conducted?
A: We started the trial more than 4 years ago with women aged 65 years and older. We reduced the age to 60 years and older to expand the eligible patient group. These older patients often have comorbidities and frequently do not want to undergo surgery. Criteria included patients with 1.5-cm or smaller invasive low-grade, stage I, luminal A breast cancers. We excluded patients with triple-negative disease and those with extensive ductal carcinoma in situ, because DCIS is often difficult to see on ultrasound. We are cryoablating the breast cancers and leaving the cancers in the women’s breast, but following them with imaging as opposed to surgical lumpectomy to ensure treatment is successful.
Q: Can you elaborate on your findings so far?
A: So far, the findings have been very good. We have completed patient accrual with about 200 patients to date. More than 100 patients have had at least 1 year of follow-up, and only two patients have recurred. We have had a more than 98% success rate with cryoablation for patients with at least 1-year follow-up. We also have patients with 2-, 3- and 4-year follow-up with no recurrences.
Q: What are the clinical implications of these preliminary findings?
A: For a certain cohort of patients, we can potentially offer them a nonsurgical procedure with cryoablation that we perform in the office in less than 1 hour. None of the patients who had the procedure experienced significant side effects, and most patients can walk out of the room and go have lunch afterward.
Q: Are there any challenges that need to be worked out?
A: The main challenge is how to follow these patients. We are following them with mammography, but some ask how we can tell if the cancer has been fully treated. It requires a new way of looking at the follow-up imaging. A challenge is to educate everyone on the new imaging findings.
Q: When do you anticipate final results to be available?
A: We hope to have good follow-up data on all patients by 2022. At that point, if we have results similar to those that we have now, we will be able to say it is successful. If that happens, I believe we may be able to start using this as an alternative to surgery for a certain group of patients. – by Jennifer Southall
Tomkovich KR, et al. Cryoablation as a primary treatment of low-risk breast cancers: An interim update of the Ice 3 Trial. Presented at: Radiological Society of North America Annual Meeting; Nov. 25-30, 2018; Chicago.
For more information:
Kenneth R. Tomkovich, MD, can be reached at Princeton Radiology, 419 N. Harrison St., Princeton, NJ 08540; email: firstname.lastname@example.org.
Disclosure: Tomkovich reports a consultant role with Scion Medical Technologies LLC and a scientific advisory board role with IceCure Medical Inc.