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The Extent of Axillary Lymph Node Clearance Required Following Detection of Sentinel Node Micrometastases
Mary F Dillon1, Brian D Hayes, Cecily M Quinn
1Department of Surgery, St. Vincent's University Hospital, Dublin, Ireland. maryfdillon@hotmail.com
Abstract:
Sentinel node (SN) micrometastases are an indication to proceed to axillary clearance. The aim of this study is to determine the extent and level of axillary clearance required for patients with SN micrometastases. All patients with SN micrometastases which were followed by axillary clearances from 1999 to 2007 were identified. Slides were reviewed by a histopathologist to detail characteristics of SN micrometastases including size and site. The SN micrometastases and primary tumor characteristics were correlated with the presence and level of non-SN micrometastases. Fifty patients who had micrometastases followed by axillary clearances were identified. Of those 18% (n = 9) had non-SN metastases.Seven patients had metastases to level I, one patient had metastases to level I and III and one patient had non-SN metastases to level III only. No patient had metastases to level II. Patients with non-SN metastases had very limited number of non-SNs involved (maximum 2 non-SNs). No variable, including site of the micrometastasis, was predictive of non-SN metastases. In patients with SN micrometastases, a limited level I axillary clearance can be justified in view of the low number of additional nodes involved and in particular, the low (4%) rate of spread to level II ⁄ III nodes.
Insights
Sentinel node (SN) micrometastases necessitate axillary clearance. This study suggests limited level I clearance may suffice due to infrequent spread to other axillary levels in breast cancer patients.
Area of Science:
- Oncology
- Surgical Pathology
- Breast Cancer Research
Background:
- Sentinel node (SN) micrometastases often prompt completion axillary lymph node dissection.
- Determining the optimal extent of axillary clearance is crucial for patient management.
Purpose of the Study:
- To evaluate the extent and level of axillary clearance needed for patients with sentinel node micrometastases.
- To correlate SN micrometastasis characteristics with non-SN involvement.
Main Methods:
- Retrospective review of 50 patients with SN micrometastases undergoing axillary clearance (1999-2007).
- Histopathological analysis of SN micrometastases (size, site) and non-SN metastases.
- Correlation analysis between primary tumor/SN characteristics and non-SN metastases.
Main Results:
- 18% of patients with SN micrometastases had non-SN metastases.
- Non-SN metastases were primarily located in level I (88%), with no involvement of level II.
- The number of involved non-SNs was limited (max 2), and no predictive factors for non-SN spread were identified.
Conclusions:
- A limited level I axillary clearance may be adequate for patients with SN micrometastases.
- The low rate of spread to levels II/III (4%) supports conservative surgical approaches.
- Further research could refine criteria for axillary clearance extent in this patient group.
