Upstaging to invasive ductal carcinoma after mastectomy for ductal carcinoma in situ: predictive factors and role of sentinel lymph node biopsy.

Routinely performing SLN biopsy for patients undergoing mastectomy for a preoperative diagnosis of DCIS is overtreatment, because the prevalence of SLN metastasis was low. SLN biopsy can be omitted for most patients. In particular, we suggest omitting SLN biopsy for patients who have lesions of ultrasound category 0-3, who have neither a mass nor NMA detected by ultrasound, or whose initial diagnosis was made based on a specimen obtained by methods other than CNB.