Validation of TAD in HER-2 with More Than 2 Lymph Nodes

This study aims to determine whether axillary treatment can be further de-escalated in patients with HER2-positive breast cancer, as this group has shown good responses to certain targeted therapies. It focuses on reducing the need for extensive axillary surgery (known as axillary lymphadenectomy or AL), which can cause complications, by using a less invasive procedure called Targeted Axillary Dissection (TAD). This method combines the removal of sentinel lymph nodes and previously marked nodes, allowing for an assessment of treatment response without needing to remove all lymph nodes. Currently, this method is used in patients diagnosed with axillary disease involving fewer than two axillary nodes. Main Objective: To evaluate whether axillary lymphadenectomy can be avoided in HER2-positive breast cancer patients with more than two affected axillary nodes who respond well to chemotherapy before surgery. Secondary Objectives: Analyze the oncological treatment response in these patients. Determine how many affected nodes respond to the treatment. Evaluate whether the number of affected nodes at diagnosis limits the possibility of performing TAD. Compare methods for locating the affected nodes. Verify the concordance between marked nodes and sentinel nodes. Methodology: This is a multicenter, prospective descriptive study. Women with HER2-positive breast cancer who receive chemotherapy before surgery will be included. Those who show a good axillary response will be offered the TAD procedure, followed by lymphadenectomy, to assess the sensitivity, specificity, false negatives, and true positives of the technique. Clinical and radiological data will be collected to analyze outcomes and complications. Significance: The TAD procedure has already allowed this hospital to reduce extensive axillary surgeries by 30%, preventing associated complications. This study seeks to confirm whether this approach is safe and effective in a specific group of HER2-positive breast cancer patients with more than two affected nodes at diagnosis. If successful, it could lead to a change in how these patients are treated, reducing risks and improving their quality of life.