Pre-surgical cryoablation in ≤ 2 cm ER + /HER2-tumors. Prognostic factors for the presence of residual invasive carcinoma

Abstract

Background: Breast cancer remains the most commonly diagnosed cancer in women. Breast-conserving surgery (BCS) is the standard approach for small low-risk tumors. If the efficacy of cryoablation is demonstrated, it could provide a minimally invasive alternative to surgery.

Purpose: To determine the success of ultrasound-guided cryoablation in achieving the absence of Residual Invasive Cancer (RIC) for patients with ER + /HER2- tumors ≤ 2cm and sonographically negative axillary nodes.

Materials and methods: This prospective study was carried out from April 2021 to June 2023, and involved 60 preoperative cryoablation procedures on ultrasound-visible, node-negative (cN0) infiltrating ductal carcinomas (IDC). Standard diagnostic imaging included mammography and tomosynthesis, supplemented by ultrasound-guided biopsy. MRI was performed in patients with associated intraductal carcinoma (DCIS) and an invasive component on core needle biopsy (18 out of 22 cases). All tumors were tagged with ferromagnetic seeds. A triple-phase protocol (freezing-thawing-freezing) with Argon was used, with an average procedure duration of 40 min. A logistic regression model was applied to determine significant correlation between RIC and the study variables.

Results: Fifty-nine women (mean age 63 ± 8 years) with sixty low-risk unifocal IDC underwent cryoablation prior to surgery. Pathological examination of lumpectomy specimens post-cryoablation revealed RIC in only one of 38 patients with pure IDC and in 4 of 22 mixed IDC/DCIS cases. All treated tumors had clear surgical margins, with no significant procedural complications.

Conclusions: Cryoablation was effective in eradicating 97% of pure infiltrating ER + /HER2-tumors ≤ 2cm, demonstrating its potential as a surgical alternative in selected patients.

Keywords: Breast cancer; Cryoablation; Early stage; Infiltrating ductal carcinoma; Low risk; Ultrasound guidance.

Fig. 1

Flowchart. 70 Participants proposed by the hospital’s multidisciplinary committee for breast-conserving surgery and pre-surgical cryoablation. Eleven of them were excluded because they did not meet the inclusion criteria. Note: ^aDCIS: Ductal Carcinoma In situ. ^bIDC: Infiltrating Ductal Carcinoma. ^cAJCC: American Joint Committee on Cancer

Fig. 2

(a) Gas argon bottle and intuitive user interface with eight needle connection ports. (b) Cryoablation needle IcePearl 14G. (c) Iceball visible during the needle test. (d) Range of ablation zone sizes in ellipsoidal and spherical shapes

Fig. 3

A 70-year-old female with pure invasive ductal carcinoma (IDC) measuring 19mm located in the upper inner quadrant of the right breast. (a) Percutaneous ultrasound-guided technique. (b) Irregular 19mm nodule with a Sirius seed located within the tumor (blue arrow). (c) Schematic representation of the procedure using the IcePearl needle. (d) Cicatricial fibrosis and hemorragic necrosis post-cryoablation. Absence of infiltrative component

Fig. 4

A 45-year-old woman diagnosed with invasive ductal carcinoma (IDC) in the right lower outer quadrant of the right breast. The figure illustrates the process of cryoablation and subsequent pathological analysis of the excised specimen. (a) A poorly demarcated nodule visible by US of 14 mm. (b) The MRI reveals a mass-like uptake with spiculated borders. (c) The Ice ball generated by IcePearl needle has engulfed the tumor. (d) Intense post cryoablation changes with a hemorrhagic central zone devoid of malignancy. Within the periphery zone of the steatonecrosis, nests of DCIS and several 2 mm foci of RIC are observed (arrows). Note: RLO right lower-outer quadrant, RIC residual invasive cancer, DCIS Ductal Carcinoma In situ

Fig. 5

Analysis of Cryoablation’s Efficacy in 60 early and low-risk Breast Cancer. Results Diagram. (a) Global efficacy with five instances of failure. (b) Efficacy in pure IDC cases. Out of 38 cases, one resulted in failure. (c) Efficacy in mixed IDC cases. Out of 22 cases, four resulted in failure. (d) Among 38 pure IDC cases, an infiltrative component was absent in 37 cases, while residual invasive cancer (RIC) was present in 1 case. Among 22 mixed IDC cases, absence of residual infiltrative component was observed in 18 cases, and RIC was present in 4 cases

Fig. 6

Macroscopic and microscopic images of the surgical specimen with 14G seed after cryoablation of a 12 mm HR + Her2- Ki 67:10 Luminal A IDC/DCIS tumor. (a) Radiographic representation of the surgical specimen revealing the coexistence of the tumor, the seed, and a peripheral region displaying post-cryoablation fat necrosis (indicated by blue arrows). (b) Macroscopic view of the specimen marked with ink. (c) One of the serial fillets through the center of the hemorrhagic necrosis * with (Sirius) seed. (d) Two-millimeter foci of Residual Invasive Cancer (RIC) distant from the region of fat necrosis marked by the dashed line and in proximity to the specimen’s periphery, maintaining separation from the inked margin. ypT1aN0Mx. Note: IDC Infiltrating ductal carcinoma, DCIS Ductal carcinoma in situ, RIC Residual invasive cancer