Authors' objectives:

To review and analyze the evidence relating to possible health benefits, adverse effects and costs of periodic mammographic screening of women aged age 40 to 49 years, in the absence of any reasons for suspicion of breast cancer.

Authors' results and conclusions: Inference from direct evidence:Combination of the data from the 5 most recent clinical trials produces an estimate of 1% increase in annual breast cancer mortality rate. The 95% confidence interval was wide, however, ranging from 26% reduction to 28% increase in mortality. Thus, the available direct evidence does not suggest that breast cancer mortality can be reduced by screening women of that age group. Inference from indirect evidence:Notwithstanding the lack of evidence of mortality reduction in trials, the possibility cannot be excluded that a new Quebec program, using modern improved equipment, high-quality two-view mammography, a short interval between screens, strict quality control and a lower diagnostic threshold, might produce a significant reduction of mortality in younger women after a delay, perhaps of 10 to 15 years. Such potential gains must be considered in the light of the negative health effects and costs that would predictably follow. It is also possible that, even after screening for such a period, using optimal screening techniques, no reduction, or only a small reduction, in mortality would be observed.

Authors' recommendations: Public policy involving the lives of thousands of individuals and large resources should not normally be made in the absence of either direct evidence of benefit or at least, extremely powerful indirect evidence. Neither are currently available. Were there good evidence that commitment of resources of this order would result in even a 10% reduction in breast cancer mortality, the screening of younger women should surely be considered in spite of health risks, the large initial outlay required and the relatively high annual cost. To initiate screening in the absence of such evidence would require faith beyond what most individuals would consider reasonable, unless it was carried out in the context of a research study. Other output or dissemination activity: It has been well documented in official administrative correspondence that this report had a considerable influence on the position taken by the Health Department on breast cancer screening in Quebec. In November 1993, the department adopted and made public an Action Plan on Breast Cancer Screening in Quebec largely based on the recommendations made in the CETS report. The plan calls for an improvement of existing screening services and targeting activities on women 50 to 69 years old.

Authors' methods: Systematic review

Project Status: Completed

URL for project: http://www.aetmis.gouv.qc.ca/

Year Published: 1993

English language abstract: An English language summary is available

Publication Type: Not Assigned

Country: Canada

Organisation Name: Conseil d'Evaluation des Technologies de la Santé du Québec

Contact Address: Conseil d'Evaluation des Technologies de la Santé du Québec, 2021, avenue Union, #1040, Montréal, Québec H3A S29, Canada. Tel: 514-873-2563; FAX: 514-873-1369

Contact Name: aetmis@aetmis.gouv.qc.ca

Contact Email: aetmis@aetmis.gouv.qc.ca

Copyright: Conseil d'Evaluation des Technologies de la Sante du Quebec (CETS)