Sentinel Lymph Node Micrometastases In Breast Cancer: Prognostic Relevance and Therapeutic Implications

摘要

OBJECTIVE The objective of this chapter is to provide a comprehensive overview of the impact of sentinel lymph node (SLN) micrometastases (> 0.2 to <=2.0mm) on axillary recurrence rate and overall survival (OS) in breast cancer patients. INTRODUCTION The SLN procedure proved to be a reliable method for the evaluation of the axillary nodal status in patients with early-stage invasive breast cancer. Therefore, level 1 and II axillary lymph node dissection (ALND) can be omitted if the SLN is free of macrometastases. However, the clinical relevance and therapeutic implications of SLN micrometastases remain a matter of great debate. Herein, we present data from our own prospective SLN study, which will be discussed in the context of other published investigations particularly focusing on the axillary recurrence rate and OS in patients with SLN micrometastases. CONCLUSION Based on current literature and our own study results it can be concluded that there is no difference regarding axillary recurrences in patients with SLN micrometastases after SLN biopsy alone compared with either SLN-negative patients or breast cancer patients undergoing a formal ALND. In our investigation there was no statistically significant difference in OS, rate of axillary recurrences, and distant disease-free survival between patients with negative SLN and those with SLN micrometastases, who did not undergo a completion ALND. Despite a false-negative rate of the SLN procedure of about 10% as well as a substantial proportion of positive non-SLN lymph nodes in patients with SLN micrometastases, there appears to be little clinical impact of these phenomena. In fact, most SLN micrometastases do not negatively impact regional and distant disease control.