 A homogeneous technique with combined, colorimetric and isotopic SLN detection with subareolar or peri-tumoral injection will be used. This consensus combined technique has been validated by all investigators. The histopathological procedure will also be homogeneous, and validated within the group of pathologists of the Fédération Nationale des Centres de Lutte Contre le Cancer FNCLCC. Breast surgery will either be a mastectomy or conservative treatment. 