Efficacy and feasibility of the immunomagnetic separation based diagnosis for detecting sentinel lymph node metastasis from breast cancer

A purpose of this study was to establish a novel molecular diagnostic model and provide new insight into the intraoperative evaluation of the sentinel lymph node (SLN) metastasis in breast cancer. A total of 124 breast cancer patients who met the criteria of sentinel lymph node biopsy (SLNB) and underwent intraoperative biopsy were consecutively enrolled in this study. After the SLNs obtained from each patient were labeled, MOC-31 monoclonal antibody-mediated immunomagnetic separation (IMS) and flow cytometry were used to determine the expressions of breast cancer metastasis-related markers, including Mucin 1 (MUC1), CD44v6, and HER2. Alternatively, conventional intraoperative hematoxylin and eosin (HE) staining and cytokeratin immunohistochemistry (CK-IHC) were performed to detect potential SLN metastasis. The sensitivity, specificity, and false-negative rate of the three intraoperative diagnostic methods were compared and analyzed. A total of 55 positive-SLNs were found in 38 breast cancer patients using IMS, yielding a sensitivity of 86.4% (38/44), specificity of 94.7% (36/38), accuracy of 93.5% (116/124), false-positive rate of 2.5% (2/80), false-negative rate of 13.6% (6/44), positive predictive value of 95.5% (42/44), and negative predictive value of 93.0% (80/86). Patients with high expressions of CD44v6, MUC1, and HER2 in SLNs tended to have higher number of positive lymph nodes, among which the MUC1 and HER2 showed significant differences (P<0.05). Therefore, compared with conventional HE staining and CK-IHC, IMS technology has remarkably higher sensitivity and specificity and relative lower false-negative rate, thus making it an effective and feasible intraoperative detection method of SLN for breast cancer diagnosis to some extent.