During the last 10 years, the role of specific nutrients in cancer prevention and cancer treatment has been the subject of intense basic, preclinical, and clinical research. At present, the major focus of nutri­ tional oncology is on the mechanisms of carcinogenesis and their modification by nutrients and on cancer prevention studies in animals and humans. Some human epidemiological studies have confirmed the hypothesis, developed on animals, that there is an inverse relation­ ship between the intake and/or level of !3-carotene, vitamin A vita­ min E, or vitamin C and the risk of cancer, whereas others have shown no such relationship. This is not unexpected, since the protective effect of individual nutrients may be too small to be detected by epidemiological methodologies in which a single vitamin or mineral is considered as one variable. Conclusive evidence regarding the role of nutrients in human cancer prevention will come from a well­ designed human intervention study using one or more nutrients in a population that has a high risk of developing cancer. The involvement of specific nutrients in the regulation of protooncogene expression has just begun. Also, some of the results of human intervention trials are beginning to yield interesting results. A large number of interna­ tional scientists from various disciplines, including cell biology, mo­ lecular biology, nutritional oncology, epidemiology, and public health, reviewed and discussed their most recent findings. The following topics were emphasized: 1. Mechanisms of carcinogenesis; 2.

Inhalt

Nutrition and Cancer: An Overview of Present Reality and Future Goals. Mechanisms of Carcinogenesis. Two Operational Modes of Transmembrane Migration of Cyclic GMP Signal Pathway. Mechanisms of Action of Nutrients in Cancer Prevention. Counteractions of Retinoic Acid and Phorbol Ester Tumor Promoter Related to Changes in Protein Kinase Activities. Effect of Alpha Tocopheryl Succinate on Cell Differentiation and Adenylate Cyclase System. Effect of Nutrition on Carcinogenesis: Mechanisms Involving Nitrosamines. Mechanisms in Cancer Prevention by Dietary Antioxidants. Effects of Protease Inhibitors and Vitamin E in the Prevention of Cancer. Carotenoids Inhibit Chemically- and Physically-Induced Neoplastic Transformation During the Post-Initiation Phase of Carcinogenesis. Fatty Acids That Inhibit Cancer: Conjugated Dienoic Derivatives of Linoleic Acid. The Usefulness of In Vitro Assays and Animal Experiments in the Design of Chemopreventive Protocols with Beta-Carotene and Vitamin A on Tobacco Chewers. Dietary Modulation of Tobacco-Specific Carcinogen Activation. Mechanisms of Specific Nutrients in the Prevention of Cancer. Preclinical Studies in Cancer Prevention and Treatment. Reduction of Ultraviolet-Induced Immunosuppression and Enhanced Resistance to Ultraviolet-Induced Tumors by Retinyl Palmitate and Canthaxanthin. Retinoids and Prevention of Experimental Cancer. Selenium and Vitamin E in Cancer Prevention. Vitamin B6 and Cancer. Clinical Studies in Cancer Prevention and Treatment. The Nutritional Causes of Large-Bowel Cancer: Data from the Melbourne Colorectal Cancer Study and a 25-Year World Literature Overview, 1965-1989. An Intermediate Evaluation of the Nutrition Intervention Trials in Linxian, China. Control of Human Preneoplasia with Retinoids and Other Compounds. Carotenoids in Cancer Chemoprevention and Synergism with Retinol in Mastalgia Treatment. Adjuvant Immunotherapy of Breast Cancer: Prototypic Observations with Alpha-Tocopherol and Retinol.Vitamin B-6 and B-1 Status During Hormone Therapy of Gynecological Cancer. Index.