Background: Fine-needle aspiration biopsy (FNAB) is a well-documented procedure for the diagnosis and biologic characterization of breast carcinoma. In order to compare the immunocytochemical expression of biologic parameters on cytology and on histology, estrogen receptor (ER) and progesterone receptor (PgR) status, p53 protein expression, and Ki67 growth fraction were evaluated on presurgical fine-needle aspirates (FNAs) from breast carcinoma patients and on the corresponding surgical samples prior to any systemic therapy.
Methods: FNAs were performed on 104 patients with primary breast carcinoma at the time of diagnosis and subjected to immunocytochemical evaluation of ER, PgR, p53, and Ki67. The same parameters were immunohistochemically evaluated on the corresponding paraffin embedded sections.
Results: ER, PgR, p53, and Ki67 were evaluable on FNAs and on paired tissue sections in 100, 97, 68, and 84 cases, respectively. Concordance between cytology and histology was 89% for ER, 78% for PgR, 79% for p53, and 70% for Ki67.
Conclusions: The concordance between the results of immunocytochemical evaluation of ER, PgR, p53, and Ki67, on both cytology and histology, underscores the reliability of the biologic characterization of breast carcinoma by FNAB. This approach could be particularly useful in predicting prognosis and response to treatment in patients who are candidates for neoadjuvant chemotherapy and/or endocrine therapy.