Background: Whether sentinel lymph node biopsy (SLNB) should be performed in patients with pure ductalcarcinoma in situ (DCIS) of the breast has been a question of debate over the last decade. The aim of this studywas to identify factors associated with microinvasive disease and determine the criteria for performing SLNB inpatients with DCIS. Materials and Methods: 125 patients with DCIS who underwent surgery between January2000 and December 2008 were reviewed to identify factors associated with DCIS and DCIS with microinvasion(DCISM). Results: 88 patients (70.4%) had pure DCIS and 37 (29.6%) had DCISM. Among 33 DCIS patientswho underwent SLNB, one patient (3.3%) was found to have isolated tumor cells in her biopsy, whereas 1 of 14(37.8%) patients with DCISM had micrometastasis (7.1%). Similarly, of 16 patients (18.2%) with pure DCISand axillary lymph node dissection (ALND) without SLNB, none had lymph node metastasis. Furthermore, of 20patients with DCISM and ALND, only one (5%) had metastasis. In multivariate analysis, the presence of comedonecrosis [relative risk (RR)=4.1, 95% confidence interval (CI)=1.6-10.6, P=0.004], and hormone receptor (ER orPR) negativity (RR=4.0, 95%CI=1.5-11, P=0.007), were found to be significantly associated with microinvasion. Conclusions: Our findings suggest patients presenting with a preoperative diagnosis of DCIS associated withcomedo necrosis or hormone receptor negativity are more likely to have a microinvasive component in definitivepathology following surgery, and should be considered for SLNB procedure along with patients who will undergomastectomy due to DCIS.
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