Non-Axillary Sentinel Node in Breast Cancer. Are we Staging Correctly? A Multicenter Study

Purpose: The study of the sentinel lymph node is the best technique to stage, have a prognosis and decide the adequate treatment in breast cancer. The usual technique implies studding the axillary lymph node. Our work tries to identify affected nodes in other regions apart from the axilla and its possible impact in staging and treatment. Methods: The sentinel lymph node technique was performed on 1660 patients included in an observational and multicentric study designed to observe the presence of metastatic cells in axillary and non-axillary lymph nodes. Results: In 19% of the patients the sentinel lymph node was detected in non-axillary regions. In these cases metastatic cells were more frequent which could suppose a change in the stage and/or treatment. As protective factor against non-axillary nodes involvement we found the localization of the cancer in external quadrants while youth and injecting the tracer inside the tumor were found to be risk factors. Conclusions: Detecting and studding non-axillary lymph nodes in breast cancer leads to a more precise staging of the disease which could imply a change in the optimal treatment.