Outcome of patients with ductal carcinoma in situ and sentinel node biopsy.

Background: In sentinel node biopsy (SNB), tumor-positive findings, mainly micrometastases and isolated tumor cells (ITC) have been found in up to 8%-16% of patients with pure ductal carcinoma in situ (DCIS) or microinvasive DCIS (DCISM). The prognostic significance of such findings is largely unknown. The aim of this study is to examine the outcome of DCIS and DCISM patients with SNB.

Methods: A total of 280 breast cancer patients with pure or microinvasive DCIS underwent SNB between April 2001 and December 2010 at the Breast Surgery Unit of Helsinki University Central Hospital. Patient, tumor, SNB procedure, and follow-up data were gathered. The median follow-up was 50 months (range 7-123 months).

Results: Altogether, 21 patients had tumor-positive sentinel node findings. Of these, 14 were in pure DCIS patients (1 macrometastasis, 1 micrometastasis, 12 ITC) and 7 in DCISM patients (1 macrometastasis, 2 micrometastases, 4 ITC). Also, 16 patients, 10 with pure DCIS and 6 with DCISM, underwent completion axillary lymph node dissection (ALND). Only 1 of them, a patient with DCISM, had additional tumor positive finding in the ALND. During a median follow-up of 50 months (range 7-123 months) there were 5 local recurrences. One patient with pure DCIS and tumor-negative SNB developed overt axillary metastases and later also distant metastases.

Conclusions: DCIS and DCISM patients do have tumor positive findings, but a majority of these are ITC or micrometastases. In light of this study, these findings do not affect the outcome of DCIS or DCISM patients.