[The immunohistochemical detection of steroid hormone receptors in breast cancer: open problems and new perspectives].

Steroid hormone receptor analysis is a major determinant for adjuvant therapy and prognosis in breast cancer. The immunohistochemical analysis of oestrogen and progesterone receptors is a widely used method that is gradually replacing the traditional and clinically validated dextran charcoal radioactive ligand binding assay. However, the immunohistochemical method needs careful attention to ensure adequate quality assurance. The critical points to be considered include: (a) fixation of specimens; (b) antigen retrieval procedures; (c) type of antibodies used; (d) quantification of the staining; and (e) internal and external controls. The introduction of new reagents that can identify previously unrecognised isoforms of the oestrogen (beta isoform) and progesterone (isoform B) receptors may be of interest in the evaluation of prognosis and response to therapy.