Abstract:

The axillary management of breast cancer patients after neoadjuvant therapy (NAT) is undergoing optimization. Sentinel lymph node biopsy (SLNB) has become an important means for evaluating the status of axillary lymph node (ALN), especially in early-stage breast cancer patients with initially clinically negative ALN (cN0), where it can replace traditional ALN dissection (ALND) to reduce unnecessary surgical risks and complications. However, SLNB has some limitations in terms of false negative rate (FNR) and variability when applied to breast cancer patients with initially clinically positive ALN (cN⁺) after NAT. By removing ≥3 SLN, using dual tracers (such as radioactive isotopes combined with blue dye), and conducting pathological assessment in combination with immunohistochemistry (IHC), the FNR can be significantly reduced to an acceptable range (4.9%-9.1%). Moreover, various optimization schemes have been developed, such as marking ALN with radioactive iodine (MARI), targeted axillary dissection (TAD), and radioactive iodine seed placement in the axilla with SLNB (RISAS), all of which demonstrate low FNR. Not only that, non-invasive imaging techniques such as positron emission tomography and computed tomography (PET/CT), magnetic resonance imaging (MRI), conventional ultrasound and contrast-enhanced ultrasound (CEUS) can all be used to evaluate the axillary response after NAT, with varying diagnostic efficacies. This article summarized recent studies on the optimization of axillary management and SLNB diagnosis and treatment for breast cancer patients with cN⁺ after NAT.

Key words: Breast cancer, Sentinel lymph node, Neoadjuvant therapy, Axillary surgery, False negative rate