Long-term tracing and staining of carbon nanoparticles for axillary lymph nodes in patients with locally advanced breast cancer treated with neoadjuvant chemotherapy

Background: The regression of positive nodes in breast cancer after neoadjuvant chemotherapy (NAC) remains unknown. This study aimed to investigate this regression by injecting and tracing carbon nanoparticles (CNs) into the fusion node prior to NAC in patients with breast cancer. Methods: Guided by ultrasound, 0.3 mL of CNs suspension was injected in the fusion node prior to NAC in 110 patients with local advanced breast cancer. Then the patients underwent breast surgery and total axillary lymph node dissection following 2-6 cycles of NAC. The distribution by intercostobrachial nerves (ICBN) of positive nodes and black-stained nodes was researched, and the relationship between the distribution and lymphovascular invasion were investigated by response to NAC. Results: When patients were ranked by response to NAC (from sensitive to resistance), the number of positive nodes increased, as did the proportion of lymphovascular invasion, the number of black-stained nodes decreased. A significantly negative relationship was found between the number of positive nodes and the number of black-stained nodes (p < 0.001). The positive nodes in patients with sensitive consequence followed the rule from under the ICBN to above the ICBN. However, there was counterexample (skip metastasis) in the patients with resistance result. Conclusion: The regression of positive nodes follows the rule from upper to under, inner to outer in the patients with sensitive consequence to NAC. Long-term staining and tracing by CNs might provide an acceptable and feasible technique to investigate the regression of positive nodes, and would be a potential method for NAC-treated patients by using of ICBN. Trial registration: NCT 03355261. Retrospectively registered on November 28, 2017. (c) 2021 Asian Surgical Association and Taiwan Robotic Surgery Association. Publishing services by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/ licenses/by-nc-nd/4.0/).

Automated summary

In breast cancer patients who underwent neoadjuvant chemotherapy, the regression of positive nodes follows a specific pattern related to lymphovascular invasion. Long-term staining and tracing using carbon nanoparticles can be used to study the regression of nodes, providing a potential method for NAC-treated patients.