Summary

The present study evaluated the HER2 protein expression in the primary lesion related to the axillary metastasis of 20 women with breast infiltrating ductal carcinoma not submitted to neo-adjuvant therapy. The HER2 protein expression in the primary lesion and in the axillary metastasis was evaluated by immunohistochemical staining, with the use of monoclonal antibodies standardized and accepted for human investigation by the United States Food and Drug Administration (Dako HerceptestTM). In 12 patients we did not notice any differences between the HER2 expression in primary lesion and the axillary metastasis. For the other eight patients, however, we did not notice the concordance between the HER2 expression of the breast cancer and the comprised axillary lymph node; finally, in one patient, the axillary metastasis expression was significantly higher.