Accuracy of sentinel node biopsy in predicting nodal status in patients with breast carcinoma.

BACKGROUND AND OBJECTIVES

While sentinel lymph node biopsy is considered by many to have replaced axillary node dissection in the management of breast cancer, concerns remain regarding false-negative results.

METHODS

To investigate the accuracy of sentinel node biopsy, we reexamined all sentinel and nonsentinel nodes with multilevel sectioning and immunohistochemical staining in 42 consecutive cases of breast cancer in which sentinel node biopsy was performed and followed by axillary dissection.

RESULTS

By routine hematoxylin and eosin (H&E) staining, 34% of patients were found to be node positive, with no cases of false-negative sentinel node biopsy. Reevaluation of 775 negative sentinel and nonsentinel nodes with an additional two levels and immunohistochemistry identified three "node-negative" patients who had micrometastases in the sentinel node, increasing detection in 8% of cases. More important, is the fact however, that there were no cases where additional sections and immunohistochemistry identified metastases in nonsentinel nodes that had bypassed the sentinel node. The accuracy of the sentinel node in predicting the nodal status was 100%.

CONCLUSIONS

Cytokeratin immunohistochemistry will identify more patients with nodal micrometastases; however, it was unable to identify any cases where micrometastases were present in nonsentinel nodes when the sentinel node was negative. The status of the sentinel node accurately identifies the status of the axillary basin.