SLNB should be performed and is the preferred method of axillary lymph node staging if the patient is a candidate for SLNB (see BINV-D). In the absence of definitive data demonstrating a survival advantage, axillary staging may be considered an option for patients with a particularly good tumor prognosis, patients who are unlikely to compromise adjuvant systemic and/or radiation therapy options, or the elderly or those with severe comorbidities. Grade III dissection to the thoracic inlet should be performed only in cases with significant lesions in grades II and/or III. In cases of grade II lymph nodes without significant lesions, lymph node dissection should include the tissue from the lateral border of the latissimus dorsi muscle to the medial border of the pectoralis minor muscle below the axillary vein (grade I/II).