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

Background: the effects and costs of different policies forbreast cancer screening in Catalonia (Spain) were analysed,to give a basis for setting priorities and deciding on the introductionof a screening programme. Methods: the MISCAN (MIcrosimulationSCreening ANalysis) model of the natural history of breast cancerwas used. The epidemiology of breast cancer in Catalonia andthe demography of the Catalan population was taken into accountas well as the results on mortality reduction from a Swedishoverview of breast cancer screening trials. Results: the reductionin breast cancer mortality in the total female population dueto a screening programme for the age group 50–64 yearswould be 16, 12 and 9%, with screening intervals of one, twoand three years respectively. The cost-effectiveness ratios(CE ratios) for these scenarios were 924,000, 730,000 and 719,000pesetas (P_t) per life-year gained respectively (5% discounting).The most cost-effective screening scenario is the one in whichwomen aged 50–69 years are screened with an interval ofthree years with a mortality reduction of approximately 12%in the total female population (CE ratio = 694,000 P_t). Screeninguntil the age of 69 years (two year interval) was almost ascost-effective as screening the age group 50–64 yearswith a two year interval, with a reduction in breast cancermortality of 15%. Extension to under the age of 50 years resultedin diverging results depending on the assumptions for improvementin prognosis for younger women (40–49 years). Conclusion:if the extension of a two yearly screening programme for womenaged 50–64 years is considered (mortality reduction of12%), extension to older women would be more advisable, basedon proven benefits and costs, than extension to younger agegroups.