Objective:

To evaluate factors affecting axillary pathological complete response (pCR) in breast cancer patients after neoadjuvant chemotherapy (NACT) and assess the diagnostic performance of imaging modalities in detecting residual axillary metastasis, highlighting the significance of these findings in current treatment practices.

Key Findings:

• 54.9% of patients achieved no residual axillary metastasis after NACT.
• HER2 positivity and progesterone receptor negativity were significantly associated with higher rates of axillary pCR (p < 0.05).
• HER2-rich and triple-negative subtypes showed higher axillary pCR rates (85.7% and 71.4%, respectively).
• PET-CT and USG demonstrated specificities of 91.2% and 84.6%, respectively, with corresponding NPVs of 74.02% and 76.52%.

Interpretation:

PR-positive and HER2-negative tumors have a lower likelihood of achieving axillary pCR, indicating the need for careful evaluation. Imaging modalities like USG and PET-CT can aid in axillary assessment but should not replace pathological staging, emphasizing their role as complementary tools.

Limitations:

• Retrospective design may introduce selection bias.
• Limited generalizability due to single-center study.
• Potential biases in imaging assessments.

Conclusion:

Further prospective randomized trials are needed to identify patient groups that may safely avoid axillary dissection after NACT, particularly focusing on the role of imaging in clinical decision-making.