Retrospective analysis of sentinel node localization in multifocal, multicentric, palpable, or nonpalpable breast cancer.

UNLABELLED Multicentric or multifocal breast cancer is considered as one of the limitations for sentinel lymph node (SLN) localization. We did a retrospective analysis to evaluate the success rate, sensitivity, accuracy, and negative predictive values of SLN localization in multicentric or multifocal breast lesions. METHODS Fifty-nine patients with multifocal or multicentric breast lesions proven by either fine-needle aspiration (19/59), core biopsy (39/59), or lumpectomy (8/59) underwent SLN localization. Of these patients, 46 had SLN localization by both radiocolloid and blue dye, and 13 had SLN localization by radiocolloid alone. Approximately 10 MBq (99m)Tc-labeled unfiltered sulfur colloid in 0.3-0.4 mL were injected intradermally over the 1 or 2 breast tumor locations 2-4 h before surgery. During surgery, vital blue dye was injected intraparenchymally in 4-6 places around the tumor. All lymph nodes with counts of >10 times that of the background counts, whether or not blue dye positive, and all blue dye-positive lymph nodes, whether or not radiocolloid positive, were excised and labeled accordingly. All lymph nodes underwent frozen sectioning and were examined by hematoxylin and eosin and immunohistologic (cytokeratin) staining. RESULTS Of the 59 patients, 48 had axillary lymph node dissection irrespective of the results of pathologic examination of the SLN. The success rate, sensitivity, negative predictive value, and accuracy were 93%, 100%, 100%, and 100% using the radiocolloid probe, 87%, 100%, 100%, and 100% using blue dye, and 93.5%, 100%, 100%, and 100% using combined methods, respectively. Concordance between blue dye and radiocolloid was 91% (the incidence of the number of sentinel nodes detected was 37.5%, 30.3%, 10.7%, and 21.4% for 1, 2, 3, and 4 or more lymph nodes, respectively). Metastatic lymph node involvement was found in 39.5% of patients. CONCLUSION The sentinel node localization approach showed a high negative predictive value in breast cancer patients with multifocal or multicentric lesions, contrary to the common belief of significant false-negative results in these patients.