Abstract P3-13-07: Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial
Authors: Garcia-Tejedor A , Guma A , Soler T , Valdivieso A , Petit A , Contreras N , Chappuis CG , Falo C , Pernas S , Anselem A , Fernandez-Montoli E , Pla MJ , Burdio F , Ponce J 
Published: May 2019

PURPOSE: To study the safety and efficacy of ultrasound-guided percutaneous radiofrequency ablation (RFA) as local treatment for breast cancer and to intraoperatively evaluate the margin status after RFA in comparison with lumpectomy.

MATERIAL and METHODS: Preliminary in vitro RF ablation experimentation with two mastectomy specimens was performed to test the electrode, practice the ultrasound technique and evaluate the macroscopic and microscopic effects of RF. Then, aprospective, randomized open-label phase II clinical trial (NCT02281812) was conducted in a single institution from 2013-2017. Forty subjects, mean age 64 (range 46-86), with ductal infiltrating carcinoma of the breast ≤2 cm were randomly assigned to RFA plus lumpectomy or lumpectomy alone. Margin status, tumor cell viability (TCV) after RFA (by nicotinamide adenine dinucleotide (NADH) and Cytokeratin 18 (CK18) staining), adverse events and local recurrences were evaluated by univariable and multivariable analyses (SPSS statistical software).

RESULTS: In the experimental design with mastectomies, the only procedural complication was a skin burn at the entrance site of the electrodes. We learned that the tip of the electrodes should cut cross the tumor by at least 10mm.

The clinical trial includes two groups: study group (n=20) and control group (n=20). NADH and CK18 staining demonstrated absence of TCV after RFA with at least one of the two techniques. The percentage of intraoperatively affected surgical margins was higher in the control group although local adverse effects after surgery was higher in the RFA treatment arm. Three study subjects presented local infection (two had partial irradiation of the breast) and none in the control group. Median follow up was 25 months (range 1–83). No recurrence or second surgery was required during the study period.

Outcomes RFA group (n = 20)Control group (n=20)p valueSpecimen weight (median, gr)42 (24-80)27 (11-60)0.004Specimen volume (median, ml)369 (259-847)201 (100-602)0.004Positive margin (intraoperative)4/20 (20%)11/20 (55%)0.022Pathological size (median, mm)11.5 (5-20)10.5 (6-16)0.07Local Adverse effect8/20 (40%)1/20 (5%)0.01Breast Inflammation5/20 (25%)1/20 (5%)0.182Breast Infection3/20 (15%)0/20 (0%)0.23RFA: radiofrequency ablation. n=number of subjects

CONCLUSION: RFA seems effective in the cases considered and could be more accurate than lumpectomy in terms of obtaining more free margins. Surgical excision associated with RFA leads to a higher amount of local adverse effects, especially if combined with partial irradiation of the breast. RFA could be considered as a less invasive treatment in tumors smaller than 20 mm; however, this warrants further investigation.

Citation Format: Garcia-Tejedor A, Guma A, Soler T, Valdivieso A, Petit A, Contreras N, Chappuis CG, Falo C, Pernas S, Anselem A, Fernandez-Montoli E, Pla MJ, Burdio F, Ponce J. Is radiofrequency ablation better than lumpectomy for margin status in breast cancer? Results of a randomized clinical trial [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P3-13-07.