Steroid hormone receptors, MIB-1, p53, and c-erb-B2 expression on breast cancer: Comparison of immunohistochemistry on cell block and fine needle aspiration and tissue sample, in northwest Iran

Fine-needle aspiration of breast cancer often provides moderate cellular material that is representative of the tumors. These samples can be used not only for cytological diagnosis but also to obtain information on the prognosis and likely response to therapy by using immunohistochemical staining studies. We assessed the degree of correlation between prognostic biologic markers by means immunohistochemistry (IHC) on cytoblock obtained from fine-needle aspiration (FNA) and immunohistochemical determination on their corresponding tissue sample of five markers; steroid hormone receptors, MIB-1 (Ki-67), p53, and c-erb-B-2 (Her2/neu) in 45 mastectomy of breast cancer. Interobserver reproducibility ranged from 93 to 100%, depending on the marker. A good correlation was observed between immunostaining assessment on cytoblock and on their corresponding tumor tissues as follows: Ki-67 (87%), ER (80%), PR (93%), p53 (96%), and c-erb-B-2 (76%). We conclude that cytoblock prepared from fine-needle aspiration specimens of breast cancer is a useful and noninvasive procedure when planning neoadjuvant treatment.