Italian Multicentric non inferiority two-arm randomized clinical trial to verify that the experimental treatment (omission of axillary lymph node intervention) in the presence of sentinel lymph node metastases does not lead to a significant worsening in survival or in the risk of locoregional recurrence compared to standard treatment (removal of I-II level of axillary lymph nodes).

Detailed Description:

The trial is a non-inferiority trial; patients, depending on intra-operative or post-operative sentinel lymph node assessment, are randomly assigned to one of the two intervention groups:

group 1: removal of I-II level of axillary lymph nodes (standard treatment). Removal of at least 10 lymph nodes is recommended.

group 2: no axillary lymph nodes dissection (experimental treatment). Patients for whom sentinel lymph node cannot be found, will undergo complete dissection of the axillary cavity as required by international guidelines.

After surgery, according to their bio-pathological profile and to the international guidelines criteria, patients will be able to receive:

• no further treatment
• complementary radiotherapy
• adjuvant medical therapy (chemo and / or hormone therapy).

Patients will be checked for at least 5 years in the following ways:

• six-monthly clinical examination for the first 5 years and yearly thereafter
• mammography + annual breast ultrasound
• annual axillary ultrasound in cases not subjected to dissection.

Inclusion Criteria:

• Age: 40 ≤75 years old
• Breast cancer with infiltrating histology
• Tumor size ≤50 mm (T1 - T2)
• Clinically and ultrasound node-negative (cN0) breast cancer
• No distant metastases (M0)
• No neoadjuvant therapy
• Negative history of previous infiltrating neoplasm
• Maximum number of metastatic sentinel lymph nodes: 2
• Lymph node macro-metastases > 2mm

Exclusion Criteria:

• Pregnancy or breastfeeding in progress
• Inflammatory breast cancer
• Breast cancer in situ
• Synchronous contralateral breast cancer
• Co-morbidities such as to preclude the possible use of adjuvant therapy
• Conditions that make it impossible to carry out a regular follow-up
• Other malignancies within the previous 3 years (except carcinoma in situ of the uterine cervix, basalioma or squamous cell ca or non-melanoma skin ca)
• Breast cancer with non-infiltrating or inflammatory histotype
• Tumor size> 50 mm
• No sentinel lymph nodes identified
• No positive sentinel lymph nodes (pN0)
• Positive sentinel lymph node number > 2
• Lymph node micro-metastases <= 2