Implications of Isolated Tumor Cells in Sentinel Lymph Nodes of Breast Cancer Patients

Purpose: Sentinel lymph node (SLN) biopsy has replaced unnecessary axillary dissection in breast cancer surgery except when the nodes are positive for macrometastasis. But guidelines for isolated tumor cells (ITCs) found in SLNs has not yet been established and further study is ongoing. The goal of this study was to consider the implication of the isolated tumor cells found in the SLNs of Korean breast cancer patients. Methods: Between September 2003 and March 2008, 985 primary breast cancer patients underwent SLN biopsy. On reviewing the medical records, 81 patients were found to have ITCs in SLNs without macrometastasis or micrometastasis. ITCs were detected by serial sectioning and immunohistochemistry. Results: The mean number of detected SLNs was 3.5±1.7. Thirty three patients had multifocally distributed ITCs and 9 had ITCs in multiple SLNs whose N stage was N0 (i＋). Completion axillary dissection has been performed in 9 patients and 3 of them (33.3%) finally were found to be N1 or N1mi. Conclusion: The characteristics of ITCs are not clear yet and their prognostic value is still under investigation. Until the significance of ITCs found in SLNs become definite, axillary dissection should be more aggressively considered.