Diagnosis and therapy of breast cancer since the population-wide introduction of a mammography screening programme in the ambulant health care systemof Luxembourg

Introduction: The efficiency of mammography screening in highly specialized diagnostic centres has been well proven for the age group 50-64 years. Few data is available concerning the value of such a screening under decentral ised, population-wide conditions. Since 1992, a mammography screening progr am (LMSP) organised in this way is being offered in Luxembourg to the age g roup 50-64 years. Materials and methods: The early outcome Indicators of this screening progr amme were evaluated retrospectively. The pathological characteristics of al l the diagnosed breast cancers, their diagnosis and their therapy before (1 989) and after (1993) the introduction of the mammography screening program me were compared and analysed. Results: The early outcome indicators of Luxembourg's mammography screening programme were just below the comparable values of other specialised centr es. Since the introduction of this programme one notes a significant increa se in the number of open breast biopsies in comparison to the period before the screening programme (p = 0.0001), with a highly significant increase i n benign biospies (p = 0.00001). The ratio cancer/all biopsies dropped non- significantly from 0.35 to 0.28 (p = 0.09). Atypical proliferative hyperpla sias and in situ carcinomas increased significantly in number (p = 0.01) as did the number of early invasive cancers (p = 0.0015). The lymph node stat us did not change significantly although there was an increase in node-nega tive tumours (p = 0.11). The number of conservative surgical procedures inc reased significantly (p = 0.00001). In the age group analysis these changes were significant only in the age group 50-64 years (p = 0.0002). All these changes were not only due to the evolution within the screening cohort, bu t also to the changes among the tumour patients diagnosed outside the scree ning programme. Conclusion: The early outcome indicators of this mammography screening prov e a possible efficiency even under population-wide, non-specialised screeni ng conditions. Nevertheless, studies over a longer period of time will be n ecessary to analyse the evolution of cancer-specific mortality.