Is Sentinel Lymph Node Biopsy Necessary for Ductal Carcinoma In Situ Patients Undergoing Mastectomy?

Current treatment guidelines for ductal carcinoma in situ (DCIS) treated with mastectomy recommend sentinel lymph node biopsy (SLNB). In the modern era, there is a trend toward minimizing invasive staging and treatment of the axilla. In this study, we seek to determine the role of SLNB in patients undergoing mastectomy for the treatment of DCIS.

Patients undergoing mastectomy were identified from our institution's SLNB database from 2012 to 2016. Patients were included if core needle biopsy demonstrated DCIS. Patient demographics, tumor characteristics, and pathologic variables were abstracted.

Of 187 patients undergoing mastectomy with SLNB from 2012 to 2016 for DCIS or invasive ductal carcinoma, 39 (21%) were diagnosed with DCIS on core biopsy. Mean age was 57 years. 70% were Caucasian, 18% were African American, 8% were Asian, and the remaining 5% were unknown. One patient (3%) had positive nodes on SLNB and underwent axillary lymph node dissection. Of those with DCIS on core biopsy, 14 (36%) were upstaged to invasive disease on final surgical pathology, including the patient with positive SLNB. Of the remaining 25 (64%) patients with DCIS on final pathology, 0 (0%) had SLNB positivity.

Only 3% of patients with DCIS undergoing mastectomy were found to have SLN metastases. However, a significant number of patients (36%) were upstaged due to invasive cancer. Although limited by a small sample size, our results suggest that SLNB should still be recommended to patients undergoing mastectomy for DCIS on core needle biopsy due to the high rate of upstage rate to invasive disease.