Mammography benefit in the Canadian National Breast Screening Study-2: A model evaluation†
Article first published online: 15 MAR 2004
Copyright © 2004 Wiley-Liss, Inc.
International Journal of Cancer
Volume 110, Issue 5, pages 756–762, 10 July 2004
How to Cite
Rijnsburger, A. J., van Oortmarssen, G. J., Boer, R., Draisma, G., To, T., Miller, A. B. and de Koning, H. J. (2004), Mammography benefit in the Canadian National Breast Screening Study-2: A model evaluation. Int. J. Cancer, 110: 756–762. doi: 10.1002/ijc.20143
The study sponsor had no role in the conduction of the study or the writing of the report. The authors declare no conflict of interest.
- Issue published online: 11 MAY 2004
- Article first published online: 15 MAR 2004
- Manuscript Accepted: 18 DEC 2003
- Manuscript Revised: 16 DEC 2003
- Manuscript Received: 17 SEP 2003
- Health Care Insurance Board (the Netherlands)
- breast cancer;
- clinical breast examination;
- Canadian National Breast Screening Study-2
The CNBSS-2 among women aged 50–59 did not show any significant difference in breast cancer mortality between a control arm screened annually by CBE and a study arm screened by CBE and mammography. Because of this design, the benefit of screening compared to no screening could not be evaluated. We therefore conducted a modeling effort to estimate the benefit of mammography or CBE compared to no screening. We incorporated demographic, epidemiologic and screening characteristics of the CNBSS-2 in MISCAN. Stage-specific sensitivities of CBE, with and without mammography, and breast cancer incidence rate in the trial were estimated by comparing observed trial data with model predictions. We predicted the number of breast cancer deaths for both study arms of the CNBSS-2 and in the absence of screening, assuming improvement in prognosis by early detection. We estimated a 24–29% higher breast cancer incidence rate in the CNBSS-2 than the average Canadian rate. Estimated sensitivity of CBE (control arm) varied from 0.29 to 0.48 for stage T1c and from 0.6 to 0.65 for stage T2+. Estimated sensitivity of CBE supplemented with mammography (study arm) varied from 0.5 to 0.79 for stage T1c and was 0.95 for stage T2+. Expected breast cancer mortality reduction by annual CBE screening is 20.5% compared to no screening. Estimated breast cancer mortality reduction by mammography screening compared to no screening for the CNBSS-2 fell within the range 13.6–34.1%. Enrolled women had above average risk. Screening sensitivity in both arms was high. A benefit of mammography screening is supported by our modeling of the CNBSS-2 results. © 2004 Wiley-Liss, Inc.