Randomized study of mammography screening — preliminary report on mortality in the stockholm trial
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In March 1981, 40,318 women in Stockholm, aged 40–64, entered a randomized trial of breast cancer screening by single-view mammography alone versus no intervention in a control group of 20,000 women. The attendance rate during the first screening round was 81 per cent and the cancer detection rate was 4.0 per 1000 women. The detection the rate fell to 3.1 per 1000 in the second round, which was completed in October 1985. During 1986 the controlled design of the study was broken and the contro women were invited once to screening which was completed the same year. A total of 428 cases of breast cancer were thus diagnosed in the study group and 439 in the adjusted control group. After a mean follow-up of 7.4 years the number of breast cancer deaths in the study and control groups was 39 and 30 respectively. The relative risk of breast cancer death (screening versus control) was 0.71 (95 per cent confidence interval: 0.4–1.2). Among women older than 50 years at entry the relative risk was 0.57 (95 per cent confidence interval: 0.3–1.1). Cancer deaths among women under 50 were few and perhaps because of this no mortality reduction was seen in this age group. The estimate of mortality reduction lies between the results from two earlier Swedish randomized controlled trials.
Key wordsbreast cancer mammography screening mortality
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- 4.UK Breast Cancer Detection Working Group: Trial of early detection of breast cancer: Description of method. Br J Cancer 44: 618–627, 1981Google Scholar
- 5.Chamberlain J, Coleman D, Ellman R, Moss SM: First results on mortality reduction in the UK trial of early detection of breast cancer. Lancet ii: 411–416, 1988Google Scholar
- 8.Andersson I, Aspegren U, Janzon L, Landberg T, Lindholm K, Linell F, Ljungberg O, Ranstam J, Sigfüsson B: Mammographic screening and mortality from breast cancer: the Malmö mammographic screening trial. Br Med J 297: 943–948, 1988Google Scholar
- 11.World Health Organisation: Manual of international statistical classification of disease, injuries, and cases of death; based on the recommendations of the eighth revision conference, 1965, and adopted by the nineteenth world health assembly. Geneva: WHO, 1969Google Scholar
- 13.Andersson I: Radiographic screening for breast carcinoma. Program and primary findings in 45–69 year old women. Acta Radiol (Diagn) 22: 185–194, 1981Google Scholar
- 20.Tabár L, Gad A, Holmberg L, Ljungqvist U: Significant reduction in advanced breast cancer. Diagn Imag Clin Med 54: 158–164, 1985Google Scholar
- 21.Fagerberg G, Baldetorp L, Gröntoft O, Lundström B, Månsson JC, Nordenskjöld B: Effects of repeated mammographic screening on breast cancer stage distribution. Acta Radiologica 24: 465–473, 1985Google Scholar
- 22.Tabár L, Fagerberg CJG, Day NE: The results of periodic one-view mammography screening in a randomized, controlled trial in Sweden, Part 2: Evaluation of the results. In: Day NE, Miller AB (eds) Screening for breast cancer. UICC Technical Report Series, Geneva, 1988, pp 39–44Google Scholar