This overview of diagnostic aspects of breast cancer focuses on high-risk features and risk determinants of newly disease. It offers a unique update enabling the quantification of the risk at diagnosis. This book differs from others on breast cancer by its focus on risk, and by providing a comprehensive summary of modern diagnostic approaches to the disease. Individual chapters provide not only an update on more conventional diagnostic techniques such as those derived from epidemiology, mammography, pathology and hormone receptors, but also insight into the newest aspects of modern technological approaches, including kinetic determinations with the help of flow cytometry, labeling index, oncogenic assessment, immunology, chromosomal assessment and in vitro cultures. There is increasing evidence that a refined analysis of all risk factors will offer clinicians valuable information on the type and degree of disease aggressiveness in a given patient. Such information will be essential in deciding the individual therapeutic strategy so as to avoid overtreating low risk individuals and undertreating high-risk cases. Correct determination of the risk at diagnosis will likely lead the way to an increase in cure rates and to improvement of the overall cost-benefit ratio of breast cancer treatment.