Cancer causes a quarter of all deaths in England and Wales. There is great professional and public interest in cancer trends, but no satisfactory source to which to turn to find information about these trends and explanation of them. It is even more difficult to know where to turn for information on trends in factors causing cancer. This book presents new analyses that bring together data on cancer trends in England and Wales since 1868. Detailed consideration is given to the reasons for changes in rates of cancer, in relation to a wide range of risk factors and preventive factors. Data are presented with figures and tables describing long-term trends in more than fifty factors that may affect the risk of cancer, including AIDS, asbestos exposure, cancer screening, childbearing, diet, smoking, and ultraviolet radiation. Particular attention is given to trends in recent decades, but historical trends are also considered.