The Third International Copenhagen Symposium on Detection of Breast Cancer afforded a further opportunity for scientists from all over the world to come together and present important papers con cerning breast cancer and early diagnostic procedures. The Sympo sium was an opportunity to learn from extensive screening proce dures carried out at outstanding centers in the United States, Sweden, the Netherlands, and England. Furthermore, the Sympo sium dealt with new modalities such as ultrasonography, magnifi cation techniques, and magnetic resonance; and very important contributions concerning self-examination, fine needle aspiration biopsy, and radiation risks were presented. A whole section was also dedicated to the highly important cooperation between radiologist, surgeon, and pathologist. It is our sincere hope that a study of the different aspects of breast cancer presented in this volume will encourage the reader to join in the struggle against this dreadful dis ease. December 1986 S. Brunner B. Langfeldt Contents B. Nielsen Image Quality in Mammography: Physical and Technical Limitations . 1 S. A. Feig, B. M. Galkin, and H. D. Muir Clinical Considerations in Selection of Dedicated Mammography Units . . . . . . . . . . . . . . . . . . . . 15 . . . E. A. Sickles The Role of Magnification Technique in Modern Mammography . . . . . . . . . . . . . . . . . . . . . . . . . . 19 B. M. Galkin, S. A. Feig, P. Frasca, H. D. Muir, and R. Z. Soriano Imaging Capabilities and Dose Considerations of Different Mammographic Units . . . . . . . . . . . . . . . . . . 25 . . . E. A. Sickles Computed Tomography Scanning, Transillumination, and Magnetic Resonance Imaging of the Breast . . . . . . . . . . . 31 A. G. Haus Recent Trends in Screen-Film Mammography: Technical Factors and Radiation Dose . . . . . . . . . ."

Endocrinologic investigations during pregnancy have focused in the last decades on placental hormones, the maternal endocrine system and maternal fetal interactions. Less is known about the fetus itself and the interaction of fetal hormonal response and physiological parameters. In this book physiologists, pediatricians and obstetricians active in experimental studies in both physiology and endocrinology combine both aspects of investigations. Historical remarks on the endocrine development of the fetus are followed by observations of the hormonal control of the cardiovascular system. Basic mechanisms of fetal endocrine control such as brain development, fetal growth, fetal behaviour, and thermoregulation are given particular consideration. Finally, carbohydrate metabolism and the mechanism of parturition are outlined.

H.-J. Senn Adjuvant Chemotherapy (ACT) of breast cancer has now emerged as one of the controversial su):>jects in clinical and also experimental oncology. Driven by growing frustration about stagnating cure rates in breast cancer [1,4] and stimulated by elegant demonstration of highly curative effects of adjuvant systemic therapy in animal models [6, 11] and in several childhood neoplasias [15], researchers introduced ACT to the primary treatment of breast cancer with great hope some 15 years ago. After a first wave of isolated "historic" trials with generally limited but in one case remarkable success [5, 9], a second generation of ACT studies was initiated by NSABP investigators and oncology centers in Europe [2, 6, 13]. These trials were well conducted statistically and diagnostically, and all in the early 1970s included a surgical control arm. Early and intermediate beneficial effects on relapse-free survival (RFS) after 2-3 years median observation time then prompted a whole series of ACT studies in breast cancer. These "third-gener ation" studies usually regarded some positive influence of ACT as a given fact, dropping surgical control regimens and comparing different ACT regimens, hopefully in a prospective, randomized way 1984 Fig. 1. The mushrooming of adjuvant studies in breast cancer XII Introduction [reviews in 3, 14]. The "mushrooming" of ACT studies in breast cancer during the last 10 and especially 5 years is demonstrated in Fig. 1, and it gets really cumbersome even for the insider to keep on top of the multitude of sometimes conflicting data.

Few subjects in gynecology, let alone in medicine in general, have provoked such inter est or study as cervical cancer. Although the wealth of monographs and books publish ed on the subject would seem to obviate the need for more, the great advances made in the medical sciences and in gynecological experience and techniques in recent years call for, if not require, a new book on cervical cancer to bring together the latest ideas and trends in its methods of study, diagnosis, and treatment. Although precancerous lesions have become more common, the number of women developing invasive cervical carcinomas has not increased, owing in part to programs of patient education, in part to screening examinations sponsored by the government. The gynecologist is now able to detect with well-tried and proved techniques precan cerous states of the cervix, and to treat these effectively before they become invasive cancer. Accordingly, recent interests in cervical cancer have shifted from the classic descrip tion of invasive carcinoma to newer studies of cause, diagnosis, therapy, and terminol ogy of its precursors. As the reader will learn, epidemiological studies as guides for the future account for, and justifiably so, an important part of this book. New knowledge about changes in the morphology of cervical carcinoma confirms its dependency on hormonal stimulation. Furthermore, modem experiences serve to explain which therapy is best. Overlapping of concepts and opinions between some chapters could not be avoided."

The account of "neonatal sterilization" is the story of the advocates of direct effect of steroids on the gonads and those who believed in the indirect influence, mediated through the hypothalamus and/or the pituitary gland. As often happens in biology, both convictions represent the same image seen from different perspectives. Prof DC Johnson (Kansas City, KS) reminisced the beginning of the story in a letter to me. I am paraphrasing parts of the letter with his permission. "As a starting point we could pick the life-long research of Emil Steinach ... " Steinach recognized the influence of testes on the develop ment of accessory sex organs in 1894, described virilization of females and feminization of males in 1913, and identified the controlling influence of the hypophysis on the gonads in 1928. He reviewed his work in a book Sex and Life, Forty Years of Biological and Medical Experience (E Steinach and L Loebe!; Faber and Faber, London, 1940). He got on the wrong road in later years and that is the reason everybody seems to have forgotten him. He presented his hypothesis that estrogen has a direct effect upon the testes, i. e. hormone antagonism, at the 1st International Congress on Sex Research in 1926.

The Interfaces of Perinatal Addiction Ira J ChasnofT In the last few years, problems associated with drug use in pregnancy have become endemic. As cocaine has become the drug of choice for millions of Americans, including pregnant women, as AIDS has become more commonly recognized in women and infants, and as legal cases have begun to raise the question of fetal abuse, no professional group has come forward to serve as advocate for this special population of substance abusers. Meanwhile, however, physicians, nurses, social service agencies and public health officials have all been faced with increasing numbers of infants showing the detrimental effects of their mothers' drug use. Although problems of substance abuse in pregnancy have received increasing attention in the medical literature since the early 1970s, there has recently been a very rapid increase in the number of articles published related to this field. The reasons for this new interest are easily understood when current statistics from the National Institute on Drug Abuse are reviewed 1. Although patterns of abuse of alcohol, marijuana, heroin and other substances by women of childbearing age have changed very little over the last ten years, the incidence of cocaine use in this special population has been rising rapidly, a reflection of cocaine's increasing popularity among the general population of the United States.

The examination of the human fallopian tubes was, until recently, restricted to observations on gross anatomical disposition and tubal patency. These studies, for decades, were the domain of doctors and physiologists whose primary interest was population control and family planning, funded largely by organisations and agencies seek ing alternatives to steroidal contraceptives. For a "worrying" but short period after the birth of Louise Brown in 1978 as the conse quence of successful in-vitro fertilisation and embryo transfer, the fallopian tube was considered to be "dispensable" given that the metabolic milieu in which human fertilisation takes place could be effortlessly reproduced in a Petri dish, in in-vitro fertilisation procedures. However, a number of factors have acted together to renew in terest in the fallopian tube, namely new techniques in cell biology, microinstrument developments (in particular in imaging), an inter disciplinary transfer of skills from interventional radiology and car diology to gynaecology, the surgeon's wish to improve surgical tech niques, and better techniques to monitor early pregnancy. These factors have led surgeons to develop the new diagnostic and ther apeutic strategies and techniques listed here. This volume contains contributions from the majority of keynote speakers at a conference held in London in April 1992 from which its title is derived. Better diagnostic procedures should lead to the implementation of rational effective treatments.

The European School of Oncology came into existence to respond to a need for information, education and training in the field of the diagnosis and treatment of cancer. There are two main reasons }Vhy such an initiative was considered necessary. Firstly, the teaching of oncology requires a rigorously multidisciplinary approach which is difficult for the Universities to put into practice since their system is mainly disciplinary orientated. Secondly, the rate of technological development that impinges on the diagnosis and treatment of cancer has been so rapid that it is not an easy task for medical faculties to adapt their curricula flexibly. With its residential courses for organ pathologies and the seminars on new techniques (laser, monoclonal antibodies, imaging techniques etc.) or on the principal therapeutic controversies (conservative or mutilating surgery, primary or adjuvant chemotherapy, radiotherapy alone or integrated), it is the ambition of the European School of Oncology to fill a cultural and scientific gap and, thereby, create a bridge between the University and Industry and between these two and daily medical practice. One of the more recent initiatives of ESO has been the institution of permanent study groups, also called task forces, where a limited number of leading experts are invited to meet once a year with the aim of defining the state of the art and possibly reaching a consensus on future developments in specific fields of oncology.

The most meaningful reward to clinicians and researchers is the absence of recurrent malignancy in their patients. While in some patients the disease will be cured by resection alone, in other similarly staged cases the disease will recur despite adequate loco regional and systemic therapies. Hence, risk assessment is a complex issue with many related or unrelated prognostic factors determining outcome. The purpose of this volume is to review some of the most relevant prognostic factors of newly diagnosed breast cancer, focusing on fea tures determining the magnitude of risk. The ultimate value of establishing the significance of each prognostic factor in a given patient will be the resulting ability to plan individu alized therapies for patients at different risk of recurrence at the time of diagnosis. To secure the maximum benefit for high-risk patients, while avoiding undue toxicity in those with low-risk lesions, a well-integrated analysis of all known prognostic factors will be essential in the early postdiagnos tic period. In addition to well-established staging criteria such as axillary nodes, tumor size, receptors, scanning and radiographic examinations, the more sophisticated labora tory techniques, as discussed by several authors herein, will playa crucial role in risk assessment. Most of them, - ploidy determination, oncogenes, tumor markers, monoclonal anti bodies, growth factors, etc. -are presently available in only a minority of treatment centers.

Contraceptives have always provided ground for controversy. This book describes and discusses latest findings concerning the advantages as well as hazard and risk factors of contraception. The clinical impact of oral contraceptives on metabolism is particularly highlighted. In addition, behavioral methods, intrauterine devices, implants and modern approaches in animal and clinical research in the field of immunization against pregnancy are considered. Last, but not least, the book summarizes the complex ethical, religious and political aspects of family planning and contraception.

The anticipation of seeing and having to manage patients suffering from sensory disorders of the urinary tract brings dismay and foreboding to the urologist. This stems from his experience of the time that these patients take up, both at the stage of initial interview and subsequently during numerous consultations over periods of months and years. This and the largely unsatisfactory response to various forms of therapy in the past are reason enough for this bold attempt to define with objectivity the notoriously subjective disorders of interstitial cystitis, urethral syndrome and prostatodynia. In writing this book the principal aim of the authors has been to define these three entities concisely and to describe the investiga tional methods which are required to establish the diagnosis in each case. The importance of this cannot be overestimated since, when the label of one or other of these conditions is attached to a patient, further objective consideration of the case is-endangered. The casual attribution of these sensory diagnoses to inappropriate cases is already on record as having dulled clinical awareness and led to oversight of progressive disease and its sometimes avoidable conse quences."

It is about 15 years since the first presentation on uteroglobin was given to a group of developmental biologists, reproductive physiologists, and geneticists who had gathered in November 1966 at Konstanz (Germany). In the following decade so much knowledge was accumulated that a special symposium seemed appropriate. This was organized as a satellite symposium to the International Congress of Endocrinology at Hamburg and brought together 50 scientists at Aachen. These scientists, working in the field of pro teins and steroids, in early pregnancy, recognized the impact of what had been reported, and many of them later agreed to contribute to this booN. and thus to present their research d, ta available until December 1980. The present volume covers a relatively broad spectrum of data and observations which shed some light on preimplantational embryonic life and on the supports and obstacles provided by the maternal organism with respect to final accomplishment of normal im plantation and establishment of pregnancy. The book will serve both as a textbook and as a scientific dictionary for Ph.D. students, postdoctoral fellows and advanced scientists working in this area. The course of early pregnancy depends very much on a proper balance of steroid hor mones, and the induction of protein synthesis by steroid hormones is one of the well known fundamental processes in cellular differentiation and embryonic development."

I am honored to have been invited to write a foreword for this book, because tumors of the yolk sac have been a preoccupation of mine since the days of my residency, now more than 3 decades ago. At that time, a 3-year-old boy died of a testicular cancer of unknown histo genesis. It was bad enough that the child died, but it bothered me even more that medical science did not know the histogenesis of the tumor that destroyed him, and I decided to study testicular cancer. For re search training I sought out F. J. Dixon, who had written the Armed Forces Fascicle on testicular tumors. Dr. Dixon and I showed that embryonal carcinoma was a multipoten tial malignant stem cell that differentiated into the three embryonic germ layers of murine teratocarcinoma. This led to the idea that the normal counterpart of embryonal carcinoma must also be multi potent, and we focused on the preimplantation embryo for the histo genesis of the tumor. This idea was strengthened by the discovery that embryonal carcinoma cells made embryoid bodies in the ascites and it was possible to observe the development of these bodies in vitro. These observations led to the idea that embryonal carcinoma was a caricature (gross misrepresentation) of early development, and car cinomas in general were a caricature of the process of renewal of their normal counterpart."

The epididymis has great significance in the reproductive biology of the male and it is gaining recognition as an organ worthy of study in its own right - where the secretory and absorptive activities of one tissue (the epithelium) profoundly modify the function of another (the spermatozoon). Apart from cases of epididymal agenesis or physical blockage, however, it is not yet known to what extent mal functions of the epididymis contribute to "unexplained" male infer tility, but its importance as a target for antifertility agents in the male is now widely appreciated. This monograph evolved from two lectures on epididymal func tion given at the National Research Institute for Family Planning, Beijing and the Sichuan Provincial Family Planning Research Insti tute, Chengdu, China in 1983. In order to stress for this audience the central importance of the epididymis in fertilisation, and so highlight its potential for attack by antifertility agents, the talks attempted to put the epididymis in reproductive perspective by stressing the func tional development of the sperm cells during their sojourn in the epididymis, rather than merely listing the changes observed in them."

In 1909 a short contribution entitled "Geriatrics" was published in the New York Medical Journal. According to this article, old age represents a distinct period oflife in which the physiologic changes caused by aging are accompanied by an increasing number of pathologic changes. We now know that the organs of the body age neither at the same rate nor to the same extent and that physiologic alterations are indeed superimposed by pathologic changes; as a result of the latter phenomenon the origins and course of illnesses in the elderly can present unusual characteristics. The frequency of concurrent disorders in the elderly entails the danger of polypragmatic pharmacotherapy, i. e., the use of various drugs to combat various disorders while neglecting the possibly adverse combined effects of these drugs. To obviate this danger, special knowledge in the field of geriatrics, the medical branch of gerontology, is necessary. Geriatrics is constantly increasing in importance owing to the near doubling of life expectancy over the past 130 years and to the improved diagnostic and therapeutic techniques made available by medical pro gress. The rapid recent development of experimental gerontology has played an essential role in enabling us to understand the special features of geriatrics. This progress has, however, been accompanied by such a vast increase in the volume of literature on the subject that specialists in the field can scarcely maintain an overall perspective of new publications."

The World Congress of In Vitro Fertilization and Alternate Assisted Reproduction, held in Jerusalem, Israel, 2-7 April, 1989, was the sixth in the sequence of these Congresses, but was the first to emphasize the major importance and the place of assisted reproductive technologies in the treatment of infertility. The eternal City of Jerusalem witnessed the gathering of more than 1500 participants from allover the world who shared and exchanged knowledge and up-to-date experience in this ever-evolving field. The high quality scientific contributions to the Congress culminated in the publication of this Proceedings. It embraces all-important aspects in the field of in vitro fertilization and alternate assisted reproduction. Papers on controversies and diversities of methods to stimulate the ovaries, imaging techniques, basic research and state-of-the-art papers on ovarian physiology, the role of GnRH and its analog, clinical aspects of IVF treatment and cryopreservation, up-to-date techniques in assisted reproductive technologies that are quickly developing in conjunction with IVF, were included. When should IVF be preferable to surgery? What are the ex pected up-to-date world results and what are the psychological, moral, ethical and religious implications? These are all the concerns of the treating team and are addressed here. Male factor infertility remains a frustrating problem, but advances in the understanding of sperm-egg interaction, sperm evaluation and preparation are reported. Micromanipulation emerges as a possible alternative to bring some relief to this problem, but it also promises to be central in promoting the field of prenatal genetic analysis."

Volume 3 of this series is concerned with geriatric aspects of surgical specialties: gynecology, orthopedics, general surgery, otorhinolaryn gology, and ophthalmology. Closely associated with these specialties is anesthesiology. Dermatology has an intermediate position between surgical and nonsurgical fields. The peculiarities of physiological and pathological aging of otgans and the consequences for diagnosis and therapy - presented in the first two volumes - are of great significance, especially for surgical special ties. There are a large number of pre-, intra-, and postoperative problems in multimorbid geriatric patients, e. g., coronary insufficiency, brady arrhythmias, hypertonia, and hypotonia. While as recently as the tum of the century the age of 65 years was viewed as a contraindication for sur gery, today even older patients undergo operations on aortic aneurysms, bypass operations for coronary sclerosis, pulmonary resections, and abdominosacral resections of rectal carcinomas, for example. Pre requisite for successful surgery at an advanced age is good pre- and postoperative care of multimorbid patients. Physiological changes of the lungs with aging, the increased frequency in pneumonia and pulmonary just a few embolisms with age, and the decrease in receptors, to give examples, confront anesthetists with difficulties. The maxim "in old age a little less" is also applicable in this field. Only improved experimental gerontological research, possibly reaching even into anesthesia, will provide objective data for anesthesia in elderly patients. The skin is an organ that experiences characteristic qualitative and quantitative changes in old age."

Obstetric fistula is as old as mankind. While the incidence has diminished progressively with better health care in Western societies, the situation has changed little in many developing countries. Fistulae of pelvic organs, often monstrous defects, still are a major complication of child-birth causing misery to uncounted young women, and if they cannot find help in one of the very few hospitals with trained specialists, they became urological cripples losing everything: family, home and job. The magnitude of the problem is illustrated by some figures given by Reginald and Catherine Hamlin-about 700 fistula patients treated each year-a total of over 10,000 cases operated upon in their fistula hospital in Addis Ababa, Ethio pia. Most of these injuries could be prevented by better health care at the village level as some studies have shown conclusively. The incidence of fistula is an indicator of the standard of health and obstetrical care. The author of this book-Obstetric Fistula-is an internationally known Australian gynaecologist who for many years has been interested in all aspects of gynaecological urology, especially urinary stress inconti nence, other forms of involuntary loss of urine, and associated gynaeco logical conditions. He has devised a number of new operations to treat pelvic defects. Robert Zacharin's interest in obstetric fistula was a con sequence of his surgical activity in developing countries."

Since the pioneering work of Donald and his first Lancet paper in 1958, the use of ultrasound in obstetrics and gynaecology has evolved rap idly. The introduction of grey scale techniques enhanced our ability to identify different tissues on the basis of their texture. However, it was the introduction of the linear array real-time scanner in the mid seven ties that changed ultrasound from being an "eccentric art form" to a readily available and usable technique. This led to the first reports of the diagnosis of neural tube defects using ultrasound by Campbell, as well as the establishment of fetal biometry. In the midst of this activity the parallel development of the transvaginal probe by Kratochwill went almost unnoticed by most gynaecologists. Yet the application of this technique has since had a major impact on many areas of gyna ecological practice, and on infertility in particular. Since the demon stration of transvaginal follicle aspiration, the vaginal route has become standard for most invasive ultrasound guided gynaecological procedures. The relatively new technical advance of transvaginal colour Doppler may potentially have just as great an impact. The introduction and use of transvaginal colour flow imaging has facili tated the study of vascular changes within the pelvis.

In few areas of medicine is progress more spectacular than in the field of prenatal diagnosis. New clinical techniques such as chorion villus sampling, detailed ultrasound scanning and cordocentesis are being evaluated by obstetricians, and refinement of biochemical testing is widening the scope of maternal serum screening. In the laboratory, dramatic advances in molecular biology are occurring: families at risk of genetic disease can be investigated with gene probes, and preimplantation diagnosis of the embryo is now becom ing a reality. These technical advances have important ethical and practical implications, among which will be a further increase in public expectations of the standards required of antenatal services. Clini cians will need a high degree of skill to inform healthy women about the options for screening normal pregnancies, and to counsel high-risk women about the benefits and limitations of prenatal diagnosis. Obstetricians, scientists and health service managers will face the difficult task of deciding how prenatal diagnosis can be made available to women in a caring and cost-effective way. Recognising the rapid progress in this field, the Royal College of Obstetricians and Gynaecologists made prenatal diagnosis the subject of its 23rd Study Group. An international panel of leading researchers, whose expertise ranged from molecular biology to philosophy, was invited to participate in a three day workshop, with time for in-depth discussion as well as the presentation of papers.

In the past decade fetal heart rate monitoring has become a generally ac cepted method for fetal surveillance during pregnancy and labor. Although its importance has been doubted recently, I personally feel that this method has become an important obstetric tool. It has not only improved our knowledge about fetal behavior and fetal condition throughout gesta tion, but it has especially improved fetal surveillance during labor; the most dangerous period of human life has never been as safe as nowadays. The only people who can question the advantage of fetal heart rate moni toring are those who did not experience the period before fetal heart rate monitoring was generally introduced. The first paper on the history of fetal heart rate monitoring takes us back to the beginning of fetal surveillance and provides an introduction to the different aspects of fetal observation which are covered later in this volume. Common practices of fetal surveillance in different countries are discussed, and the paths that future developments will take are suggested. An outline of the physiological aspects of fetal heart rate regulation is fol lowed by discussion of the pathophysiology with which the obstetrician is very often confronted."

HRT and Osteoporosis is a response to the increasing awareness among both the medical profession and the general public that ovarian failure is an important cause of osteoporosis and that much of the bone loss after the menopause can be prevented by oestrogen treatment. There is now an urgent need on the part of women, their doctors and those responsible for public health policy for practical guidance on such questions as the safety and acceptability of long-term treatment with sex hormones, the economic costs and benefits of such treatment, and the role of specialists and GPs in promoting and monitoring hormone replacement therapy. All these issues and more are considered here. The book comprehensively reviews current knowledge of the subject and gives recommendations for clinical practice and future research.

It will be a long time before the quality of this profusely illustrated book is overtaken and the present spate of books on the subject of obstetric ultrasound may, as a result, suffer a numerical set-back - especially with translation into English which will "deliver the milk on everyone's doorstep". Two of the authors studied in our department in Glasgow and worked like If there are any rewards for teaching, then we humble Scots who demons. have had the privilege have had more than our share as a result of the pride with which we regard our pupils. In my own old age and looking back over the last thirty years, the innumer able difficulties, set-backs and disappointments have been more than compen sated for by those who have turned the subject from a laughable eccentricity (as I have at one time experienced) into a science of increasing exactitude. This transformation has come about, not by any efforts of mine, but by the enthusiasm and ingenuity of those who would probably have achieved as much on their own if given the encouragement which I ultimately received in Glasgow University life. Limbo must be the expected lot of most of us ordinary mortals but the work lives on. And so, in this reminiscent and philosophical mood I beg leave to quote a little poem which I wrote at an age when young men do that sort of thing.

The first edition of "Testosterone: Action, Deficiency, Substitu tion" was published in 1990. Since then our understanding of the hormone that turns males into men has tremendously increased. Therefore, the editors felt that a second extended edition of the book is warranted in order to summarize established and recent findings in the field and to present the reader with an up-to-date is reflected by the textbook. The increased mass of knowledge growth of the volume from 14 to 20 chapters. In the updated edition the biochemistry and metabolism of androgens have been complemented by extensive information on the molecular biology of the androgen receptor and its disorders. The key role of testosterone in spermatogenesis is now better de fined. We have a more complete understanding of the psychotro pic effects of testosterone and know so much about the different target organs and functions that individual chapters deal with testosterone and the prostate, lipids and the cardiovascular sys tem, hair, bones and muscles. The general chapter on pharmacol ogy and clinical uses of testosterone, in particular in male hypo gonadism, is extended by pharmacokinetic studies on testoster one preparations and individual substitution modalities using testosterone esters as well as implants and advanced trans dermal applications. The physiologic basis and possible clinical applica tions of testosterone in non-gonadal diseases, in male senes cence, in hormonal male contraception and in transsexuals are discussed. The last chapter describes the role of "investigative" steroid biochemistry applied to tracking anabolic steroid abuse."

Starting in 1986, the European School of Oncology has expanded its activities in postgraduate teaching, which consisted mainly of traditional disease-orientated courses, by promoting new educational initiatives. One of these is the cloister seminars, short meetings intended for highly qualified oncologists and dealing with specific, controversial aspects of clinical practice and research. Another is the institution of permanent study groups, also called task forces, where a limited number of leading experts are invited to meet once a year with the aim of defining the state of the art and possibly reaching a consensus on developments and treatment in specific fields of oncology. This series of ESO Monographs was designed with the specific purpose of disseminating the results of the most interesting of the seminars and study groups, and providing concise and updated reviews of the subjects discussed. It was decided to keep the layout very simple in order to keep costs to a minimum and make the monographs available in the shortest possible time, thus overcoming a common problem in medical literature: that of the material being outdated even before publication. Umberto Veronesi Chairman, Scientific Committee European School of Oncology Table of Contents How to Read this Monograph F.CAvALLI ......... . 1 Experimental Strategies for Studying the Development of Breast Cancer with Special Reference to Steroid Hormones, Growth Factors and Oncogenes R.J.B. KING . . . . . . . . . . . . . . . . . . . . . . . . .. . . . 5 . . .