but also the possibility of intervention in specific stages. In Human behavior, including stress and other factors, plays an important role in neoplasia, although too little is known addition, variables which affect cancer development as well on the reasons for such development. Carcinogens, which as some endogenous factors can be better delineated help initiate the neoplastic process, may be either synthetic through such investigations. The topics of this volume encompass premalignant non or naturally-occurring. Cancer causation may be ascribed to invasive lesions, species-specific aspects of carcinogenicity, certain chemicals, physical agents, radioactive materials, viruses, parasites, the genetic make-up of the organism, and radiation, viruses, a quantum theory of carinogenesis, onco bacteria. Humans, eumetazoan animals and vascular plants genes, and selected environmental carcinogens. are susceptible to the first six groups of cancer causes, whe reas the last group, bacteria, seems to affect only vascular plants. Neoplastic development may begin with impairment ofJmdy defenses by a toxic material (carcinogen) which acts as an initiator, followed by promotion and progression to an overt neoplastic state. Investigation of these processes Series Editor Volume Editor allows not only a better insight into the mechanism of action Hans E. Kaiser Elizabeth K. Weisburger vii ACKNOWLEDGEMENT Inspiration and encouragement for this wide ranging project on cancer distribution and dissemination from a comparative biological and clinical point of view, was given by my late friend E. H. Krokowski.

This comprehensive account of the human herpesviruses provides an encyclopedic overview of their basic virology and clinical manifestations. This group of viruses includes human simplex type 1 and 2, Epstein–Barr virus, Kaposi's Sarcoma-associated herpesvirus, cytomegalovirus, HHV6A, 6B and 7, and varicella-zoster virus. The viral diseases and cancers they cause are significant and often recurrent. Their prevalence in the developed world accounts for a major burden of disease, and as a result there is a great deal of research into the pathophysiology of infection and immunobiology. Another important area covered within this volume concerns antiviral therapy and the development of vaccines. All these aspects are covered in depth, both scientifically and in terms of clinical guidelines for patient care. The text is illustrated generously throughout and is fully referenced to the latest research and developments.

This book describes molecular processes whose deregulation is important in the formation of tumors. The material is developed from basic cell signaling pathways to their roles in the clinical manifestation of specific cancers. Topics covered include molecular events intrinsic to tumor cells (leading to growth deregulation, extended lifespan, and the ability to invade surrounding tissue), protective mechanisms that prevent transformation (including DNA repair and epigenetic regulation), tumor-host interactions (with the endocrine system, the immune system, and blood vessel formation), and the underlying molecular defects of individual cancers.

Popular understanding holds that genetic changes create cancer. James DeGregori uses evolutionary principles to propose a new way of thinking about cancerÕs occurrence. Cancer is as much a disease of evolution as it is of mutation, one in which mutated cells outcompete healthy cells in the ecosystem of the bodyÕs tissues. His theory ties cancerÕs progression, or lack thereof, to evolved strategies to maximize reproductive success. Through natural selection, humans evolved genetic programs to maintain bodily health for as long as necessary to increase the odds of passing on our genesÑbut not much longer. These mechanisms engender a tissue environment that favors normal stem cells over precancerous ones. Healthy tissues thwart cancer cellsÕ ability to outcompete their precancerous rivals. But as our tissues age or accumulate damage from exposures such as smoking, normal stem cells find themselves less optimized to their ecosystem. Cancer-causing mutations can now help cells adapt to these altered tissue environments, and thus outcompete normal cells. Just as changes in a speciesÕ habitat favor the evolution of new species, changes in tissue environments favor the growth of cancerous cells. DeGregoriÕs perspective goes far in explaining who gets cancer, when it appears, and why. While we cannot avoid mutations, it may be possible to sustain our tissuesÕ natural and effective system of defense, even in the face of aging or harmful exposures. For those interested in learning how cancers arise within the human body, the insights in Adaptive Oncogenesis offer a compelling perspective.

The scientific basis, inference assumptions, regulatory uses, and research needs in risk assessment are considered in this two-part volume. The first part, Use of Maximum Tolerated Dose in Animal Bioassays for Carcinogenicity, focuses on whether the maximum tolerated dose should continue to be used in carcinogenesis bioassays. The committee considers several options for modifying current bioassay procedures. The second part, Two-Stage Models of Carcinogenesis, stems from efforts to identify improved means of cancer risk assessment that have resulted in the development of a mathematical dose-response model based on a paradigm for the biologic phenomena thought to be associated with carcinogenesis.