Screening for breast cancer in Catalonia - Which policy is to be preferred?

Background: the effects and costs of different policies for breast cancer screening in Catalonia (Spain) were analysed, to give a basis for setting priorities and deciding on the introduction of a screening programme. Methods: the MISCAN (MIcrosimulation SCreening ANalysis) model of the natural history of breast cancer was used. The epidemiology of breast cancer in Catalonia and the demography of the Catalan population was taken into account as well as the results on mortality reduction from a Swedish overview of breast cancer screening trials. Results: the reduction in breast cancer mortality in the total female population due to a screening programme for the age group 50-64 years would be 16, 12 and 9%, with screening intervals of one, two and three years respectively. The cost-effectiveness ratios (CE ratios) for these scenarios were 924,000, 730,000 and 719,000 pesetas (P-t) per life-year gained respectively (5% discounting). The most cost-effective screening scenario is the one in which women aged 50-69 years are screened with an interval of three years with a mortality reduction of approximately 12% in the total female population (CE ratio = 694,000 P-t). Screening until the age of 69 years (two year interval) was almost as cost-effective as screening the age group 50-64 years with a two year interval, with a reduction in breast cancer mortality of 15%. Extension to under the age of 50 years resulted in diverging results depending on the assumptions for improvement in prognosis for younger women (40-49 years). Conclusion: if the extension of a two yearly screening programme for women aged 50-64 years is considered (mortality reduction of 12%), extension to older women would be more advisable, based on proven benefits and costs, than extension to younger age groups.