Research progress of sentinel lymph node biopsy after neoadjuvant chemotherapy for breast cancer

Abstract

The feasibility and safety of sentinel lymph node biopsy (SLNB) after neoadjuvant chemotherapy (NAC) for breast cancer are still controversial in clinical practice. SLNB after NAC is feasible and safe for patients with clinically node-negative (cN0) breast cancer, while those with clinically node-positive (cN+ ) should be carefully considered. In addition to methylene blue and 99mTc-sulfur colloid tracing, some other tracing methods have been proposed in clinical studies, such as carbon nanoparticles and indocyanine green fluorescence tracing. The axillary lymph node (ALN) state of SLNB patients after NAC was associated with molecular subtyping, response to chemotherapy, residual breast tumor size, etc. Therefore, a number of factors should be considered to determine whether ALN dissection is needed. The false negative rate of SLNB after NAC can be reduced by some measures such as placing clips prior to surgery and preoperative tattooing with sterile black carbon suspension. Besides ALN, internal mammary lymph nodes is another route for breast cancer metastasis. As a low-invasive diagnostic technique, internal mammary sentinel lymph node biopsy can complete lymph node staging and pathological staging to guide treatment. This review attempts to introduce the research progress of SLNB after NAC from multiple aspects such as feasibility and safety, tracer methods, assessment of ALN status and methods to reduce false negative rate. Key words: Breast neoplasms; Neoadjuvant therapy; Sentinel lymph node biopsy; Axillary lymph node dissection; Internal mammary sentinel lymph node biopsy