Impressive time-related influence of the Dutch screening programme on breast cancer incidence and mortality, 1975-2006.

The aim of this study was to assess changes in the trends in breast cancer mortality and incidence from 1975 to 2006 among Dutch women, in relation to the implementation of the national breast cancer screening programme. Screening started in 1989 for women aged 50-69 and was extended to women aged 70-75 years in 1998 (attendance rate approximately >80%). A joinpoint Poisson regression analysis was used to identify significant changes in rates over time. Breast cancer mortality rates increased until 1994 (age group 35-84), but thereafter showed a marked decline of 2.3-2.8% per annum for the age groups 55-64 and 65-74 years, respectively. For the age group of 75-84 years, a decrease started in the year 2001. In women aged 45-54, an early decline in breast cancer mortality rates was noted (1971-1980), which is ongoing from 1992. For all ages, breast cancer incidence rates showed an increase between 1989 and 1993, mainly caused by the age group 50-69, and thereafter, a moderate increase caused by age group 70-74 years. This increase can partly be explained by the introduction of screening. The results indicate an impressive decrease in breast cancer mortality in the age group invited for breast cancer screening, starting to show quite soon after implementation.