The enormous expansion seen over the last decade in the mammo graphic detection of breast cancer lesions, especially the use of screen ing procedures for the early detection of clinically unsuspected tumors, has made it necessary to summarize the experience made by various centers in the world. The 2nd International Copenhagen Symposium on Detection of Breast Cancer afforded an opportunity of gathering scientists from all over the world to discuss the various problems of early breast cancer detection with special reference to screening procedures. This book forms a synthesis of the information presented by leading scientists from many of the world's mammo graphic centers, particularly those in Sweden and the USA. Hence, the reader will have the opportunity to study the outstanding work carried out by various institutes and centers of breast cancer screening. It is our sincere hope that a study of this volume will encourage other scientists to join in the work on screening procedures. S. Brunner B. Langfeldt P. E. Andersen Contents S. A. Feig: 1 Hypothetical Breast Cancer Risk from Mammography S. A. Feig: Benefits and Risks of Mammography 11 R. L. Egan and M. B. McSweeney: Multicentric Breast Carcinoma . . . . . . . . . . . . . . . . . . . . . . . . 28 M. B. McSweeney and R. L. Egan: Breast Cancer in the Younger Patient: A Preliminary Report 36 M. B. McSweeney and R. L. Egan: Bilateral Breast Carcinoma . . . . . . . . . . . . . . . . . . . . . . . . . . . ' 41 N. Bjurstam: The Radiographic Appearance of Normal and Metastatic Axillary Lymph Nodes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 M. Moskowitz, S. A. Feig, C. Cole-Beuglet, S. H."