Population screening for breast cancer by mammography in The Netherlands. Expectations, early results, negative effects and conditions for large-scale screening.

Recent publications have shown clearly that screening by mammography is the only method of reducing breast cancer mortality substantially. This can only be achieved, however, by regular annual screening of all women over 40 years of age. An efficiently organized screening program that guarantees optimal mammographic quality should be developed in order to avoid negative effects of population screening such as false-positive and false-negative reports.