Abstract:

Objective

To explore the clinical utility of methylene blue combined with marker clip and hook-wire localization in evaluating axillary metastatic lymph nodes after neoadjuvant chemotherapy for breast cancer.

Methods

Patients with cN1 or cN2 breast cancer who underwent neoadjuvant chemotherapy from January 2019 to December 2023 at Peking University Shenzhen Hospital were enrolled. Axillary lymph node biopsy was performed and marker clips were placed before chemotherapy. After chemotherapy，methylene blue was used as a tracer to label axillary lymph nodes， and labeled lymph node biopsy was performed. Before axillary lymph node dissection was performed， the labeled lymph nodes were positioned with hook-wires under the guidance of color ultrasound.

Results

A total of 22 patients with breast cancer was included in the study， with a median age of 42 years （range， 32～66 years）. All patients， including 18 stage II patients and 4 stage III patients， received chemotherapy with the EC-T （n=6） or TCbHP （n=16） regimen.Sixeen （16/22） patients were evaluated by PCR after chemotherapy. Lymph nodes localized with marker clips were identified in all patients during the operation. The number of lymph node biopsies during the operation was 3-5， and the total number of lymph nodes dissected was 9-38. Among the enrolled patients， 18 were detected with marker clips and stained lymph nodes， and 19 were detected with stained lymph nodes. The average detection time of the marker clip combined with methylene blue group was （13.27±1.87） min， which was longer than that of the methylene blue only group （8.89±2.28 min， P＜0.05）. However， the false negative rate of lymph nodes in the combination group （5.56%） was significantly lower than that of the methylene blue only group （31.58%， P＜0.05）. The accuracy of marker clip localization combined with methylene blue staining （77.27%） was higher than that of the methylene blue only group （59.09%）， and none of the patients had recurrence or metastasis during the postoperative follow-up period.

Conclusion

For early-stage breast cancer patients with positive lymph nodes and receiving neoadjuvant chemotherapy， ultrasonic-guided marker clip and methylene blue dual positioning combined with preoperative hook-wire positioning of axillary lymph nodes is a feasible method， which contributes to more reliable lymph node evaluation after chemotherapy with less trauma.

Key words: Breast cancer, Neoadjuvant therapy, Lymph node biopsy, Targeted axillary dissection, Methylene blue