Extra-axillary sentinel node biopsy in the management of early breast cancer

To document of our experience with EAS SNB and evaluate its impact on the staging, management and the associated morbidities of patients with early breast cancer.

A review of two prospective breast cancer databases identifying all SNB procedures performed at two affiliated breast units from 1998 to 2003.

A series of 979 patients underwent lymphatic mapping. Sentinel nodes were successfully identified in 903 patients. There were 142 cases in which lymphoscintigraphy identified EAS. In 17 cases extraaxillary sentinel nodes were identified with lymphoscintigraphy but could not be removed. There were 138 cases where internal mammary nodes (IMN) were removed. Of those IMN removed 25 were positive for metastases and in six of these cases only the IMN was positive. Of the 21 cases where other EAS were identified there was one case in which a supraclavicular sentinel node was positive. Twenty-five of the 26 positive sentinel nodes in EAS were macrometastases and one was a micrometastasis. No significant morbidity resulted from biopsy of EAS SNB. During IMN SNB there were eight pleural breeches, which did not result in pneumothoraces, and one case in which bleeding was difficult to control.

EAS SNB is technically feasible in the majority of cases. Minimal morbidity occurs after an initial learning phase. IMN SNB was shown to have significant impact on the staging and management in 18% of patients when IMNs were identified with lymphoscintigraphy. The impact of other extraaxillary lymph nodes is more difficult to assess due to small numbers. As there is little morbidity and valuable information is gained in a significant percentage of cases we strongly advocate EAS SNB.