Cryoablation of Primary Breast Cancer in Patients Ineligible for Clinical Trials: A Multiinstitutional Study

Background

Data from previous trials have shown that for a restricted population, cryoablation is a safe and effective alternative to surgery for treating breast cancer. However, data on patients who are ineligible for clinical trials is lacking. Consequently, the authors designed this retrospective study to assess the safety and outcomes of cryoablation in such patients.

Study Details

The study included 112 women (median age, 71 years) with unifocal biopsy-proven breast cancer who underwent ultrasound-guided cryoablation, with curative intent, across seven institutions between 2000 and 2021. All procedures were under local anesthesia and consisted of two freeze-thaw cycles, ensuring an ultrasound-visible ice margin of at least 0.5-1.0 cm. A biopsy was generally recommended for suspicious findings detected in the ipsilateral breast on follow-up imaging. Adjuvant therapies after cryoablation depended on local tumor board recommendations and patient preference.

Patient and Tumor Characteristics

The median largest tumor dimension on ultrasound was 1.0 cm (IQR, 0.7-1.8 cm). 53.6% of the patients had at least one comorbidity. Most tumors (78.6%) were IDC not otherwise specified, and the rest (28.6%) were DCIS. Researchers assessed the tumors as grade 1 in 54.5%, grade 2 in 35.7%, and grade 3 in 11 (9.8%). The hormone receptor status was ER+, PR+, HER2- in 87 77.7%, and triple negative in 8.9%.

Outcomes and Safety of Cryoablation

According to the findings of the study, the procedure (with a median duration of 14 minutes of free time) demonstrated a high success rate (98.2%) and a low incidence of minor adverse events (6.3%), with no moderate or severe complications. This aligns with previous systematic reviews, which showed minor and major AEs at 18% and 2%, respectively, after cryoablation. At a median follow-up of 2 years, true ipsilateral breast tumor recurrence (IBTR) occurred in 6.4% of patients, higher than in controlled trials.

Conclusion

Despite limitations such as retrospective design, Multi-institutional design leading to heterogeneity and short follow-up, based on the study, cryoablation proves to be a viable alternative for those unfit for surgery, offering good outcomes for select patients. Additionally, repeat procedures for recurrence were effective.