A multicentre prospective comparative study, comparing the use of various markers (magnetic marker Magseed, iodine seed 125I, carbon suspension) for marking a pathological lymph node in patients with breast carcinoma prior to neoadjuvant therapy and subsequent surgical treatment consisting of targeted axillary dissection.

There are two basic aims of the study

1. Prospective comparison of the reliability and accuracy of individual markers used for marking of a pathological axillary lymph node with subsequent targeted axillary dissection.
2. Comparison of the number of complications during localizing and detection of individual markers and postoperative complications.

In individual collaborating centers, these markers are commonly used in clinical practice for marking of a pathological lymph node in patients with breast carcinoma. The usual standard of practice and treatment will not be changed in any way; the patients will only be prospectively followed. The study will bring an answer to the question of which marker is the best for marking lymph nodes.

Apart from the basic demographic and other data (patient age, side of the body, size and characteristics of the tumor (typing, grading, staging), type and time of surgery, the incidence of complications during implantation or detection of the marker, number of lymph nodes, complications after surgery, and the final histological findings, also the following outcome measures will be observed:

• depth of marker implantation (measured in mm)
• marker migration (measured in mm)
• success-rate of resection of the marked lymph node - assessment, whether the lymph node was removed (yes/no) using the respective marker, expressed in percent of successful removal for the respective marker
• time from localizing the pathological lymph node using the marker to surgery (measured n days)

Inclusion Criteria:

• diagnosis of breast cancer, confirmed with a biopsy
• indication of neoadjuvant therapy
• biopsy of pathologically enlarged axillary lymph node and marking of the lymph node using one of the markers before neoadjuvant chemotherapy
• surgical treatment after neoadjuvant chemotherapy (targeted axillary dissection)

Exclusion Criteria:

• refusal to participate in the study
• another treatment protocol, which does not include targeted axillary dissection

Patients with breast cancer confirmed with a biopsy, indicated for neoadjuvant chemotherapy and axillary dissection, in whom pathological lymph nodes have been marked using one of the three examined and compared markers.

Individual participant data may be made available to other researchers upon request.