Chemoprevention is an innovative area of cancer research that focuses on the prevention of cancer through pharmacologic, biologic, and nutritional intervention. As originally described, this involves the primary prevention of initiation and the secondary prevention, delay, or reversal of promotion and progression. Several agents have demonstrated cancer preventive risk reduction in large phase three clinical trials in individuals with an increased risk of cancer. Other large trials are ongoing. There are several possible approaches to cancer prevention. Patients can decrease behaviors that put them at risk, be more vigilant in screening and surveillance, opt for surgical preintervention, and/or utilize "medicinal" approaches. The latter three areas in particular can benefit from the advances that nanotechnology can offer.This book was conceived with the idea of focusing on one a many worldwide research programs, and that is the role of different agents in the war against cancer. Metals and metal compounds have been used in medicine for several thousands of years. In this book, we present a selection of anticancer activities and cancer prevention potential for a selection of metal ions. This book comprises ten chapters dealing with variegated aspects of cancer and prevention. The chapters covered the role of many topics in cancer prevention as chemical carcinogenesis, some natural and synthetic compounds, metal ions, metals, trace elements, amino acids, surfactants, and nanotechnology.