Clip Marker Placement in Primary Lesions of Breast Cancer Patients Receiving Neoadjuvant Therapy

Overview

Neoadjuvant systemic therapy (NST) is increasingly recommended for patients with early breast cancer, and the rate of patients with pathological complete remission (pCR) is increasing due to the use of modern chemotherapy regimens and targeted therapies, especially in patients with human epidermal growth factor receptor 2 positive (HER2+) breast cancer and triple negative breast cancer (TNBC). It is therefore important to mark a lesion (with e.g. clip) before the start of NST in order to safely identify and localize a clip and (former) tumor bed after completion of NST. Reliable sonographic detection of the clip would be preferred to mammography-guided detection and marking. In addition to avoiding radiation exposure by mammography and reducing time, personnel and financial expenditure, ultrasound-guided wire marking of the clip is less painful for the patient than stereotactic wire marking. The present prospective registry study aims to evaluate how often the intramammary Tumark® Vision clip can be detected by ultrasound after completion of NST in patients with TNBC and HER2+ breast cancer and thus, in the case of pCR, how often the elaborate clipping with mammographic (stereotactic) guidance can be avoided.

Breast cancer patients whose carcinomas have an aggressive tumor biology which implies the need for chemotherapy are increasingly being treated with NST. As a standard procedure, clip placement of the suspicious lesion is performed after ultrasound-guided core biopsy or mammography-guided vacuum biopsy. Clipping is necessary to enable the clear identification of the sonographically suspicious area of the breast and safe surgical removal of the remaining tumor tissue (if any) during a later surgery, even following a good response under NST. The placement of a marker (clip) is particularly important for the precise localization of the original tumor bed in patients with pCR. There are a number of commercially available markers (clips) which are indicated for intramammary marking of a lesion and which differ in terms of shape and material. Difficulties may arise in placing the clip in the tumor or the tumor center. In addition, the clip can dislocate from the initial location and/or the clip might not be visualized during response monitoring. Evaluations of the ultrasound-visible clip made of nitinol investigated in this study showed very good results regarding marker dislocation and visibility within 7 days after inital placement.The clip, which immediately unfolds into a 3-dimensional spherical structure after insertion into the tissue, could be detected by both sonography and mammography in all 50 cases after the intervention; however, long-term data data at follow-up controls during and after NST are not available so far. According to current German guidelines, imaging-assisted wire marking is recommended without restriction before breast conserving surgery for non-palpable lesions. The clip is considered the target lesion for wire marking, which can be done under sonographic or stereotactic control. If the clip is reliably visible on ultrasound (even in patients with pCR), the stereotactic control of wire marking can be omitted. Therefore, the ability to visualize a clip in breast ultrasonography is of great importance. The present multicenter study aims to evaluate the sonographic detection rate of the intramammary Tumark® Vision clips after NST in clinical routine and the proportion of cases in which the clip cannot be detected, and thus the rate of mammography-guided wire markings.