Sentinel lymph node positivity of patients with ductal carcinoma in situ or microinvasive breast cancer

Purpose: The purpose of this study was to determine the rates of sentinel lymph node (SLN) positivity in patients with a final diagnosis of ductal carcinoma in situ (DCIS) or microinvasive breast cancer (MIC). Methods: One hundred thirty patients underwent SLN mapping from 1998 to 2003 for DCIS or MIC. Results: One hundred nine patients with DCIS and 21 with MIC underwent SLN mapping. One patient with bilateral DCIS underwent 2 SLN procedures; therefore, the results of 131 SLN procedures are included. On hematoxylin and eosin (H&E) staining, 4 of 110 patients (3.6%) with DCIS had positive SLNs. Four additional patients had positive SLNs by IHC staining only (3.6%). Two of 8 patients underwent completion axillary dissection, and neither had additional involved nodes on completion axillary dissection. One of the 21 patients with MIC had positive SLNs by hematoxylin and eosin (H&E) (4.8%), and another had an involved SLN by IHC staining (4.8%). The patient with the positive SLN by H&E had 1 additional node on completion axillary dissection. Conclusion: Rates of SLN positivity for patients with DCIS are modest, even in a high-risk population, and there is continuing uncertainty about its clinical importance. (c) 2006 Excerpta Medica Inc. All rights reserved.