- Definitive surgical treatment must be either mastectomy, or breast conserving surgery with axillary lymph node dissection (axillary lymph node evaluation can be either full axillary node dissection or sentinel LN evaluation followed by dissection if sentinel LN is positive) for operable breast cancer (pT1-4 [including inflammatory], pNO-3, and MO). Margins of resected specimen from definitive surgery must be histologically free of invasive adenocarcinoma and ductal carcinoma in-situ (DCIS). Lobular carcinoma in-situ does not count as a positive margin.