The status of breast cancer screening: a quarter of a century of research.

This article begins with a summary of the methods and results of the first randomized, controlled trial conducted to test the efficacy of periodic screening in reducing breast cancer mortality. The study was started in December, 1963 and the final phases of follow-up to determine the screening's long-term effect ended in 1986. Over 60,000 women aged 40-64 years, who were members of the Health Insurance Plan of Greater New York (HIP), were assigned at random to either a study group or a control group. The study group was offered screening examinations consisting of mammography and a clinical examination of the breast. About 67% accepted the invitation for an initial screening; a large proportion returned for 3 reexaminations at annual intervals. The control group continued to receive their usual medical care. By 10 years from entry, breast cancer deaths were reduced 30% among the study group women; over the long run of 18 years from entry, the decrease was 23-24%. The benefit from screening was found to be more certain among women who were over 50 years of age at the start of screening than among those aged 40-49 years. This article also describes research on efficacy of breast cancer screening started more recently in Sweden, the Netherlands, United Kingdom, and Canada, and reviews available findings which reinforce the results of the HIP project. Information is given on policies and guidelines being adopted in many countries regarding modalities, frequency, and ages to be included in breast cancer screening programs.

RCT Entities:   Population Interventions Outcomes