Swedish two-county trial

Impact of mammographic screening on breast cancer mortality during 3 decades

László Tabár, Bedrich Vitak, Tony Hsiu Hsi Chen, Amy Ming Fang Yen, Anders Cohen, Tibor Tot, Sherry Yueh Hsia Chiu, Sam Li Sheng Chen, Jean Ching Yuan Fann, Johan Rosell, Helena Fohlin, Robert A. Smith, Stephen W. Duffy

Research output: Contribution to journalArticle

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Abstract

Purpose: To estimate the long-term (29-year) Effect of mammographic screening on breast cancer mortality in terms of both relative and absolute effects. Materials and Methods: This study was carried out under the auspices of the Swedish National Board of Health and Welfare. The board determined that, because randomization was at a community level and was to invitation to screening, informed verbal consent could be given by the participants when they attended the screening examination. A total of 133 065 women aged 40-74 years residing in two Swedish counties were randomized into a group invited to mammographic screening and a control group receiving usual care. Case status and cause of death were determined by the local trial end point committees and, independently, by an external committee. Mortality analysis was performed by using negative binomial regression. Results: There was a highly significant reduction in breast cancer mortality in women invited to screening according to both local end point committee data (relative risk [RR] = 0.69; 95% confidence interval: 0.56, 0.84; P <.0001) and consensus data (RR = 0.73; 95% confidence interval: 0.59, 0.89; P =.002). At 29 years of follow-up, the number of women needed to undergo screening for 7 years to prevent one breast cancer death was 414 according to local data and 519 according to consensus data. Most prevented breast cancer deaths would have occurred (in the absence of screening) after the first 10 years of follow-up. Conclusion: Invitation to mammographic screening results in a highly significant decrease in breast cancer-specific mortality. Evaluation of the full impact of screening, in particular estimates of absolute benefit and number needed to screen, requires follow-up times exceeding 20 years because the observed number of breast cancer deaths prevented increases with increasing time of follow-up.

Original languageEnglish
Pages (from-to)658-663
Number of pages6
JournalRadiology
Volume260
Issue number3
DOIs
Publication statusPublished - Sep 2011

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Breast Neoplasms
Mortality
Confidence Intervals
Random Allocation
Informed Consent
Cause of Death
Control Groups
Health

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging

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Swedish two-county trial : Impact of mammographic screening on breast cancer mortality during 3 decades. / Tabár, László; Vitak, Bedrich; Chen, Tony Hsiu Hsi; Yen, Amy Ming Fang; Cohen, Anders; Tot, Tibor; Chiu, Sherry Yueh Hsia; Chen, Sam Li Sheng; Fann, Jean Ching Yuan; Rosell, Johan; Fohlin, Helena; Smith, Robert A.; Duffy, Stephen W.

In: Radiology, Vol. 260, No. 3, 09.2011, p. 658-663.

Research output: Contribution to journalArticle

Tabár, L, Vitak, B, Chen, THH, Yen, AMF, Cohen, A, Tot, T, Chiu, SYH, Chen, SLS, Fann, JCY, Rosell, J, Fohlin, H, Smith, RA & Duffy, SW 2011, 'Swedish two-county trial: Impact of mammographic screening on breast cancer mortality during 3 decades', Radiology, vol. 260, no. 3, pp. 658-663. https://doi.org/10.1148/radiol.11110469
Tabár, László ; Vitak, Bedrich ; Chen, Tony Hsiu Hsi ; Yen, Amy Ming Fang ; Cohen, Anders ; Tot, Tibor ; Chiu, Sherry Yueh Hsia ; Chen, Sam Li Sheng ; Fann, Jean Ching Yuan ; Rosell, Johan ; Fohlin, Helena ; Smith, Robert A. ; Duffy, Stephen W. / Swedish two-county trial : Impact of mammographic screening on breast cancer mortality during 3 decades. In: Radiology. 2011 ; Vol. 260, No. 3. pp. 658-663.
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AU - Tot, Tibor

AU - Chiu, Sherry Yueh Hsia

AU - Chen, Sam Li Sheng

AU - Fann, Jean Ching Yuan

AU - Rosell, Johan

AU - Fohlin, Helena

AU - Smith, Robert A.

AU - Duffy, Stephen W.

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