To evaluate the reduction of secondary lymphedema following axillary lymphadenectomy by incorporating the ARM technique during the procedure, without negatively impacting patient prognosis.

Inclusion Criteria:

Breast cancer patients with an indication for axillary lymphadenectomy according to the multidisciplinary team:

• cN0 with positive sentinel lymph node biopsy (pN+) requiring axillary lymphadenectomy: cT3; More than two axillary macrometastases; or patients undergoing mastectomy without indication for adjuvant radiotherapy
• cN1: Primary surgery; or after neoadjuvant therapy without complete axillary response and/or positive TAD (ypN+)
• cN2: Primary surgery; or after neoadjuvant therapy in luminal tumors and/or without complete axillary response in triple-negative or HER2-positive tumors, and/or positive TAD (ypN+)

Exclusion Criteria:

• Patients with prior axillary radiotherapy
• Patients with suspected metastatic involvement based on palpation of ARM lymph nodes during the surgical procedure
• Patients participating in other studies whose primary objective depends on local axillary treatment
• Patients unwilling to participate in the study