Several papers dealing with the clinical relevance of steroid hormone receptors in breast cancer have already been published. However, no publication has overviewed studies currently being conducted in Europe, nor is there a register of the european centers performing receptor assays. It has been our purpose to fill these gaps. A large majority of authors who we contacted kindly agreed to con tribute to our book. Papers were grouped into six main parts according to their contents. The abundance of clinical data relevant to receptor assays led us to add critical summaries to help the reader to form his own opinions on the subject. We would like to thank Drs. R. J. B. King, G. Contesso, L. Santi, and E. Engelsman, who helped us in this regard. We hope that this book will enable the reader to become acquainted with the present state of European steroid hormone receptor studies devoted to breast cancer treatment. We also hope that it will promote cooperation between European oncologists involved in this field of research.

Inhalt
I. Receptor Assays.- Classical Methods.- Sampling and Storage of Breast Cancer Tissue for Steroid Receptor Assays.- Routine Assays for Steroid Hormone Receptors.- Mathematical Analysis of Data from Receptor Assays.- New Methods.- Estrogen and Progestin Receptor Analysis in Human Breast Cancer by Isoelectric Focusing in Slabs of Polyacrylamide Gel.- Estrogen Receptor Analysis on Fine Needle Aspirates from Human Breast Carcinoma.- Estrogen and Progestin Receptors on Drill Biopsy Samples of Human Mammary Tumors.- The Value of Determination of Nuclear Oestrogen Receptors in Breast Cancer Biopsies.- Histochemical Methods.- Immunocytochemical Demonstration of Steroid Receptors.- Use of Fluorescent Sex-Steroid Conjugates for the Histochemical Detection of Breast Cancer Cell Receptors: A Critique.- Microscopic Visualization of Steroid Receptor Sites: A Mirage?.- I: A Critical Summary 86 R. J. B. King.- II. Quality Control.- Quality Control of Estrogen and Progesterone Receptor Analyses in Denmark.- Results of External Quality Control Trials Performed by the German Cooperative Group for Receptor Assay Standardization.- British Interlaboratory Quality Assessment of Steroid Receptor Assays.- Quality Control Program for Estradiol Receptor Determination: The Italian Experience.- Quality Control of Steroid Receptor Assays in the Netherlands.- Quality Control of Clinical Steroid Receptor Assays in Sweden.- Interlaboratory Variability in the Determination of Estrogen Receptor and Progesterone Receptor Content in Human Breast Tumors.- Standardization of Steroid Receptor Analysis in Breast Cancer Biopsies: EORTC Receptor Group.- II: A Critical Summary 136 G. Leclercq.- III. Biology of the Primary Tumor.- Estrogen Receptors and Distribution of Prognostic Factors in Primary Breast Cancer.-Influence of Intratumoral Estradiol Biosynthesis on Estrogen Receptors.- Influence of Endogenous Hormone Levels on Tumor Estradiol and Progesterone Receptors.- Inflammatory Tumors of the Human Breast: Determination of Estrogen and Progesterone Receptors.- Relationship Between Estrogen Receptors and Cellular Proliferation.- Relationship of Stromal Elastosis to Steroid Receptors in Human Breast Carcinoma.- III: A Critical Summary 176 G. Contesso, J. C. Delarue, F. May-Levin, H. Sancho-Gamier, H. Mouriesse.- IV. The Course of Disease.- Estrogen Receptor Variations in Neoplastic Tissue During the Course of Disease in Patients with Recurrent Breast Cancer.- The Prognostic Value of Progesterone Receptors in Primary Breast Cancer.- Estrogen and Progesterone Receptors as Prognostic Factors in Early Breast Cancer.- IV: A Critical Summary 199 L. Santi.- V. Treatments.- Adjuvant Treatment.- Relationship Between Estrogen Receptors and CMF Adjuvant Chemotherapy.- New Adjuvant Trials for Resectable Breast Cancer at the Istituto Nazionale Tumori of Milan.- Effect of Adjuvant Therapy in Primary Breast Cancer in Relation to the Estrogen Receptor Level.- V: A Critical Summary.- Palliative Treatment.- Endocrine Surgery in Breast Cancer.- Treatment of Advanced Breast Cancer with Tamoxifen.- Therapeutic Activity of Medroxyprogesterone Acetate in Metastatic Breast Cancer: A Correlation Between Estrogen Receptors and Various Dosages.- Estrogen Receptor Status and the Clinical Response to a Combination of Aminoglutethimide and Cortisol in Advanced Breast Cancer.- Steroid Receptors in Megestrol Acetate Therapy.- Protocols Based on Steroid Receptors: Great Britain.- Currently Active Protocols in the EORTC Breast Cancer Cooperative Group.- The Place of Hormone Receptors in the Elaboration of a Therapeutic Strategy Against Breast Cancer.- V: A Critical Summary.- VI. Prospects for Future Tests of Hormone Dependence.- Peroxidase Activity as a Marker for Estrogen Action in Rat Uteri and Human Mammary Carcinomas.- Estrogen-Induced Proteins in Human Breast Cancer Cells.- Stimulation by 17?-Estradiol of a Secreted Glycoprotein in MCF-7 Cells and Human Breast Cancer.- Estrogen Action on the Synthesis and Secretion of a Broad Spectrum of Proteins in Mammary Tumor Cells.- VII. Laboratories Performing Receptor Assays.- Austria.- Belgium (and Luxembourg).- Denmark.- Federal Republic of Germany.- France.- Great Britain.- Ireland.- Italy.- The Netherlands.- Spain.- Sweden (and Norway).- Switzerland.