This IARC Scientific Publication examines the epidemiological basis for cervical cancer screening and offers the most extensive data yet obtained on all aspects of uterine cervix cancer. The first part of this authoritative volume reviews the role of mass screening by cervical cytology and its organization in developing nations, and discusses the essential features of a centrally organized program. The second part reports the results of an international collaborative study of the effectiveness of screening programs throughout the world, concentrating on the protection given by various screening strategies. The wealth of invaluable material offered in this text forms a means of evaluating various policies and establishing a rational basis for early detection programs.