The use of sentinel lymph node biopsy in ductal carcinoma in situ

Although ductal carcinoma in situ (DCIS) does not require axillary evaluation, controversy exists regarding the use of sentinel lymph node biopsy (SLNB) in patients with DCIS diagnosed by core needle biopsy (CNB). Advocates of concomitant SLNB and lumpectomy cite the low morbidity of SLNB, the high rate of invasive ductal carcinoma in resected specimens, and the positive nodes found in 1 to 2 per cent of patients with resected DCIS despite finding no invasive component. Opponents of this practice cite the complication risk and the improbability of clinically significant axillary recurrence. We therefore proposed to determine our rate of invasive cancer in DCIS diagnosed by CNB and to determine whether SLNB at first operation would decrease return to the operating room. We retrospectively reviewed patients diagnosed with DCIS by CNB from 2003 to 2008. Standard clinicopathological data were collected and analyzed. In 110 patients, the prevalence of invasive cancer on final resection pathology was 13.6 per cent (15 of 110). Of those patients with invasive cancer, 93 per cent (14 of 15) had high-grade DCIS (P = 0.077) by CNB. Seventeen per cent (14 of 82) of patients with high-grade DCIS had invasive cancer. Of 34 patients with SLNB, three (9%) had positive nodes. Fifteen patients required re-excision to obtain negative margins, including 13 patients with invasive cancer. Five patients (4.5%) were spared additional operative intervention by initially performing SLNB. We suggest using concomitant SLNB when a high clinical suspicion of invasive cancer exists, in the presence of a palpable mass, or when mastectomy precludes future SLNB. Intraoperative margin assessment is needed to avoid return to the operating room.