Mortality from breast cancer in Ireland prior to the introduction of population-based mammographic screening.

Mammographic screening has been shown in international randomised controlled trials and case-control studies to be effective in reducing mortality from breast cancer. Ireland has a high mortality rate from breast cancer when compared with rates from other countries. Organised population-based mammographic screening for breast cancer is about to begin in Ireland. The purpose of this study was to examine current mortality from breast cancer, as well as trends in breast cancer mortality in Ireland since 1975, as a baseline against which future evaluations of the impact of screening can be carried out. Over the 23-yr period of review, mortality from breast cancer appears to have remained quite stable. Within the period, however, there is some variation in adjusted rates, most notably an increase to a peak in 1989, followed by a decrease between 1989 and 1997. Continued monitoring of recent trends is required, with in-depth analysis of possible explanations, such as changing breast cancer incidence rates, biological characteristics, therapeutic regimes and coding practices.