PURPOSE: to determine the expression of HER-2 protein in fine-needle aspirates obtained from infiltrating breast duct carcinoma and in the corresponding surgical specimens and to correlate HER-2 expression with histological grade. Methods: forty-eight smears fixed in alcohol and previously stained by the Papanicolaou technique and histological sections of corresponding paraffin-embedded tissue blocks were submitted to immunohistochemistry by the avidin-biotin-peroxidase method using a polyclonal antibody (A0485-Dako). The reactions were carried out simultaneously with antigen recovery. The results were analyzed by a semiquantitative method according to the HercepTest score. Scores of 3+ were considered to be positive. RESULTS: positivity was observed in 39.6% of the smears and in 35.4% of the respective histological sections, with almost perfect cytohistologic concordance (kappa 0.82). The method of evaluation of histological sections was found to be reproducible regarding the smears and standardized the interpretation of the results. The correlation between HER-2 positivity and histological grade was not statistically significant but there was a tendency towards HER-2 expression in less differentiated tumors. CONCLUSION: the positivity of the immunocytochemical reactions observed in smears was comparable to that obtained in the histological sections, indicating that the material obtained by fine-needle aspiration biopsies previously stained by the Papanicolaou technique can be used for the evaluation of HER-2 expression.
Fine-needle aspiration cytology; Oncogene; Invasive ductal carcinoma; Immunohistochemistry
