Interlaboratory Comparison of Estrogen Receptor Analysis in Paraffin Sections by a Monoclonal Antibody to Estrophilin (H222)

Abstract

The increased use of mammography has resulted in progressively smaller primary breast tumors. This trend has increased the need to perform immunohistochemical estrogen receptor analysis with formalin fixed, paraffin embedded biopsies. Nine laboratories participated in an interlaboratory study to determine the degree of variability of immunostaining results and their interpretation. The results of this pilot study indicate the need for standardization of assay protocols and the need to promote the use of freshly made formalin for optimum results. (The J Histotechnol 16:57, 1993)