Immunocytochemical study on the variation in estrogen receptors of primary and nodal metastases of breast cancer.

The variation in estrogen receptors (ER) between primary and regional nodal metastatic lesions was examined by an estrogen receptor immunocytochemical assay (ER-ICA) in 25 mammary carcinoma patients. The ER status was evaluated in terms of the percentage of ER positive stained cells, staining intensity and distribution of those stained cells. The overall ER status was consistent in both sites, however, the percentage of ER positive cells and the staining intensity were not always consistent. A decrease in the percentage of ER positive cells and staining intensity was demonstrated in the nodal metastatic lesions of 4 and 3 cases out of a total 14 ER positive cases, respectively. The mean percentage of ER positive cells in the nodal metastatic lesions was 57 per cent compared with 73 per cent in primary lesions. Thus, a tendency of both the percentage of ER positive cells and the staining intensity to decrease in nodal metastases as when compared with primary lesions in breast cancer was demonstrated.