Value of Sentinel Lymph Node Biopsy in Breast Ductal Carcinoma in Situ Upstaged to Invasive Carcinoma

Abstract

The role of sentinel lymph node (SLN) biopsy in patients with initial diagnosis of ductal carcinoma in situ (DCIS) is still a dilemma. Different studies are trying to define predicting factors of invasive cancer in DCIS. The aim of this study was to confirm the value of SLN biopsy in DCIS because of the invasive upstaging risk on final histology. Patients with initial diagnosis of DCIS and with axillary SLN biopsy were selected. All diagnoses were confirmed by biopsy of mammographic lesions. Surgical treatment was lumpectomy or mastectomy associated with SLN biopsy. Imprint stains were performed, and then serial sections were stained with hematoxylin and eosin (H&E) and with immunohistochemistry (IHC). A complete axillary lymph node dissection (ALND) was performed during the same surgery when a node metastasis was found. Eighty patients were enrolled in the study. Of the 61 patients who were initially diagnosed with DCIS, 12 (20%) were upstaged to microinvasive or invasive carcinoma and 9 (15%) had a metastatic SLN. Patients upstaged to invasive carcinoma had macrometastatic SLN immediately fed by a complete ALND. SLN micrometastases and isolated cells were detected by IHC and secondary complete ALND found an additional metastatic lymph node in one patient. Tumor size larger than 30 mm and mastectomy were the only significative predicting factors of upstaged disease (p < 0.0001) in our study. In patients with initial diagnosis of large DCIS programmed for mastectomy, SLN biopsy should be discussed in order to detect underlying invasive disease and to spare patients a second operating time.