Immunocytochemical evaluation of estrogen receptors in histological specimens of primary breast cancer

Immunocytochemical methods (ER-ICA) by using monoclonal antibodies were applied to determine the presence of estrogen receptors (ER) in 44 primary breast cancers in women. Of this 48% of the tumours were classified as receptor positive. In these tumours the nuclei had a clearly positive heterogenous colouration. In three cases a positive reaction was also found in benign epithelial cells of the breast. ER determinations by ER-ICA method were compared with quantitative analysis carried out by using radioligand and immunoenzymatic methods. There was a strong correlation between immunocytochemical ER evaluations and quantitative methods. We also found a correlation of the menopause state and patients age and ER content.