ESTROGEN-RECEPTOR IMMUNOCYTOCHEMISTRY - THE PROMISE AND THE PERILS

Estrogen receptor immunocytochemistry (ERICA) is favored over dextran- coated charcoal (DCC) or sucrose gradient assay (SGA) by many patholog ists and oncologists since it allows an estimation of tumor cell and t issue heterogeneity and permits assays to be performed on specimens no t suitable for DCC/SGA. Additionally, ERICA can be performed with grea ter ease and with less expense at the level of the community hospital pathology laboratory. Initially, like DCC/SGA, ERICA had to be done on fresh or frozen tumor samples or face a significant loss in sensitivi ty when applied to formalin-fixed, paraffin-embedded sections. Recentl y, several anti-estrogen receptor (ER) antibodies have appeared which can be successfully employed to assay routinely prepared tissue sectio ns if used in conjunction with new antigen-retrieval techniques such a s the microwave oven and citrate buffers. However, more work is needed to correlate results of these new procedures with biochemical ER assa ys, endocrine response, and survival before they can be reliably emplo yed as prognostic parameters. Furthermore, if any ER assay is to be us eful and valid, strict attention must be paid to details of specimen c ollection, freezing, and fixation in order to inhibit receptor degrada tion and false negative results. (C) 1994 Wiley-Liss, Inc.