Immunohistochemical determination of hormonal receptors on cell-blocks from fine-needle cytopunctures of breast carcinoma

We assessed the reliability of hormonal receptors (HR) by means of immunohi stochemisty (IHC) on cell blocks obtained from diagnostic fine-needle cytop unctures in a group of 142 primary breast carcinoma. The results were compa red to biochemical assessment (EIA) on their corresponding tissue samples ( 118 surgical specimens and 24core needle biopsies). Percentage of stained n uclei and a score incorporating the proportion erred the intensity of posit ive nuclei were evaluated. A two group classification (cutoff 10% of staine d nuclei) was used to define HR status. Highly positive tumors (greater tha n or equal to 50% of stained nuclei) were also individualized. Regarding HR status, concordance rate between immunostaining and biochemical assessment was 86.6 for ER and 76.8% for PR. Major discrepancies were found in 63% an d 15.5% of cases for ER and PR, respectively. A good correlation was also o bserved between quantitative values obtained by the two methods (r = 0.69 f or ER and 0.60 for PR). Discrepancies were mainly related to weak positive staining, values close to the respective cutoffs and when biochemical evalu ation was performed on core needle biopsies. We conclude that IHC on cell b locks prepared from fine-needle cytopuncture specimens of breast carcinomas is useful as a routine procedure for hormonal receptor determination espec ially when planning neoadjuvant treatment.