A SIMPLIFIED HISTOSCORE FOR THE ESTROGEN-RECEPTOR ASSAY IN BREAST-CANCER

Different histoscores combining the number of positive cells and the intensity of staining have been used to evaluate the estrogen receptor immunocytochemical assay (ER-ICA). Our aim was to investigate if the simple estimation of the amount of positive cells could be sufficient for the semiquantitative analysis of ER-ICA. Tissue from 51 women with ductal breast carcinoma was used. Half of each sample was processed with the quantitative assay (ER-EIA) and the other half with ER-ICA. Microscopical analysis was performed by two independent observers and classified on a simple scale from 0 to 4+. With EIA 31 cases (60.78%) were positive and 20 (39.21%) negative. With ER-ICA 29 (56.86%) had immunostaining, whereas 22 (43.13%) did not. 95.83% of the ER-ICA positive cases and 77.7% of ER-ICA negative had a good correlation with EIA values. Statistical analysis showed a high degree of correlation (r = 0.88 p 0.001). Hence, simple semiquantitative estimation in ER-ICA is sufficient to provide useful information for clinical use about ER content in tissue sections.