This is a prospective, single-center, non-randomized, non-controlled observational study.

Almost 55-62% of patients with triple-negative or human epidermal growth factor receptor 2 (HER2) positive, node-positive breast cancer achieve an axillary pathologic complete remission (pCR) after neoadjuvant chemotherapy (NAC). To avoid surgery post-NAC, it is paramount to accurately identify patients who achieve pCR in axillary lymph node (ALN). We found that patients with normal-appearing lymph nodes on computed tomography (CT) based radiomics of the axilla after chemotherapy had a lower risk of developing residual nodal disease. However, the features of CT-based radiomics for pCR ALN following NAC has not been established yet. This study aimed to assess the performance of CT-based radiomics in evaluating the response and predicting pCR of metastatic lymph nodes after NAC in breast cancer patients.

Inclusion Criteria:

• Triple-negative or HER2-positve invasive breast cancer with axillary lymph node metastasis by confirmed by fine needle aspiration or core needle biopsy.
• Underwent computed tomography for assessment of axillary lymph node status before and after neoadjuvant chemotherapy.
• Attend the study voluntarily, sign the informed consent.

Exclusion Criteria:

• Contradiction for adjuvant chemotherapy.
• Contradiction for proceeding surgery.

Triple-negative or HER2-positve invasive breast cancer with axillary lymph node metastasis: stage T1-3N1-2M0.