Sentinel Node After Neoadjuvancy In Node-Positive Breast Cancer: SANA Multicentric Study

Breast cancer (BC) is the most common malignant tumor and the one that causes the highest number of deaths among women around the world. In Spain some 25,000 new cases are diagnosed per year, which represents almost 30% of all female tumors. In Catalonia, the incidence is 83.9 cases / 100,000 inhabitants, while the national average is 50.9 cases / 100,000 inhabitants.

Thanks to screening programs and the awareness of patients and professionals, the majority of diagnosed cases are found in an early stage of the disease. In early stages, the prognosis is excellent with a 5-year survival greater than 80%.

Lymph node staging: selective sentinel node biopsy (SLNB) vs axillary lymphadenectomy The status of the axillary lymph nodes is one of the main prognostic factors. Knowing the lymph node status allows the disease to be staged and modulates locoregional and systemic treatment. Lymph node staging and management of axillary disease have changed dramatically in recent decades.

SLNB is currently the standard staging method for patients with clinically node-negative (cN0) breast cancer. When SLN is negative, axillary lymph node dissection (LND) can be omitted without prejudice to patient survival or locoregional control of the disease. In patients with a positive SLN and in those with affected lymph nodes at the beginning (cN+), LND is the standard of treatment. Morbidity associated with this technique affects up to 80% of patients and includes: chronic lymphedema of the upper limb (20-30%), seromas (50-60%) that in many cases require repeated punctures for drainage, infection of the wound (5-15%) that requires antibiotic treatment and sometimes drainage, decreased mobility of the arm or "frozen shoulder" (up to 10%) that requires rehabilitation treatment, neuropathic pain due to injury to the intercostobrachial nerve (5- 20%) and other less frequent ones such as hematoma or section of the long thoracic nerves (which produces a scapula alata) or the latissimus dorsi. It is obvious that all these complications affect the quality of life of patients and their emotional state. LND lengthens the days of hospitalization and this, together with the treatment of associated complications, substantially increases healthcare costs.

Current focus on the initial treatment of breast cancer: primary systemic treatment Advances in biological knowledge of the disease and in systemic treatments have led to an increasing number of patients with BC starting with systemic therapy, relegating surgery to a second stage. This approach evaluates the tumor response in vivo to systemic treatment and provides critical prognostic information. In addition, the decrease and even disappearance of the tumor increases the chances of offering a conservative surgery in the breast. Response rates vary according to the biological type of tumor and the treatment used, being higher for Her2+ tumors treated with chemotherapy combined with anti-Her2 antibodies.