This is a comprehensive overview of cancer, explaining how it grows and spreads in language that anyone can understand. Written for readers even with no medical background or formal knowledge of biology, it offers a clear description of the abnormal mechanisms underlying the progression of cancer, and contrasts these with the normal growth of cells. Also described are all the major types of cancer and the clinical and scientific features of malignancy. The latest research breakthroughs and advances in treatment—including gene therapy—are discussed. The role of alternative medicine is also summarized. Included are the names and addresses of helpful cancer organizations and many Internet addresses. A glossary of medical and scientific terms is provided.