Interpretation of Steroid Receptors in Breast Cancer. A Case With Discordant Estrogen Receptor Results Using ER1D5 and H222 Antibodies

Abstract

We report a case of an invasive duct breast cancer, grade 1 by Bloom and Richardson criteria, and metastatic to axillary nodes and perinodal soft tissue. Immunostaining for estrogen receptor (ER) with ERlD5 resulted in intense positive tumor cell staining with both frozen and paraffin sections. Matching studies using a different anti-estrogen receptor reagent (H222), uniformly produced negative results in 3 different assay systems (EIA-ER, ER-ICA, ER-PAR). This case reveals a discrepancy between reactivity of ERlD5 and H222 that may indicate the presence of outlaw ER variants. It also illustrates the interpretation problems that can arise with new antibodies that have not been fully validated, particularly if the results are used in therapeutic decision making. (The J Histotechnol 18:331, 1995)

Keywords:

• breast cancer
• estrogen receptor
• immunohistochemical staining