THE CONTROVERSY surrounding sentinel node biopsy for ductal carcinoma in situ (DCIS) is not new. The study by Intra et al1 in the March issue of the ARCHIVES supports avoiding routine sentinel node biopsy for DCIS because of the low risk of nodal metastases.
By definition, DCIS cannot spread; it is not an invasive malignancy. Any evidence of breast epithelium in a lymph node from a patient with this disease represents either an inaccurate diagnosis or perhaps displacement of epithelial cells by tumor manipulation, such as a preoperative needle biopsy. If the cells are not displaced epithelium, but rather metastatic breast cancer, then the diagnosis of DCIS is not possible. Most likely, a sampling error has occurred, resulting in underdiagnosis. This is understandable because the pathologist can, in practice, only examine a small portion of the DCIS during routine histopathologic assessment. Although some authors advocate routine sentinel node biopsy to detect underdiagnosis, this is not prudent for patients who have had their previous tumor completely excised because of the low risk of underdiagnosis and the necessity of a second operation.
Richard J. Bleicher, Armando E. Giuliano. The Selective Use of Sentinel Node Biopsy in Ductal Carcinoma In Situ. Arch Surg. 2003;138(5):489. doi:10.1001/archsurg.138.5.489