This book is a comprehensive review of recent research on cancer risk associated with various kinds of medical treatment. It covers radiotherapy and chemotherapy given for cancer and for other diseases, surgery and the special case of survivors of a first cancer in childhood. It is aimed primarily at practising clinicians, to provide them with a current review of cancer risks associated with various treatment options available for serious disease, and to help them achieve the best balance of risk and benefit for each patient. It will also be of interest to research workers in epidemiology and basic clinical science for the insights it provides into cancer etiology and the possibilities of devising more effective but less risky treatments. Perceptions of risk arising from medical treatment are often formed by rare but dramatic complications. This book provides a thorough and dispassionate review of all the evidence on one major group of diseases--the malignant neoplasms, or cancers--which may be caused by medical treatment, and sets these long-term but important risks against the immediate benefits obtained from the treatment.