Book excerpt: This much anticipated Third Edition provides a comprehensive presentation of the global burden and patterns of cancer occurrence, along with new developments in our understanding of cancer causation and prevention. Special attention is given to epidemiologic approaches that incorporate molecular biomarkers based on genomic and other emerging technologies, providing new insights into the role of genetic predisposition and gene-environment interactions in cancer induction. In addition, new chapters are included on social class disparities in cancer incidence and mortality, the role of obesity and physical inactivity in cancer etiology, the potential effects of electromagnetic fields and rediofrequency radiation, and the principles of cancer chemoprevention. The textbook is organized into five sections: Basic Concepts; The Magnitude of Cancer; The Causes of Cancer; Cancer by Tissue of Origin; Cancer Prevention and Control. In this new edition, Drs. David Schottenfeld and Joseph F. Fraumeni, Jr. have enlisted three distinguished Associate Editors: Drs. Jonathan Samet of Johns Hopkins University, Graham Colditz of Harvard University and Alice Whittemore of Stanford University.