Breast cancer screening, with particular reference to the concept of 'high risk' groups.

An overview is presented of the salient aspects of the DOM-project of breast cancer screening carried out in the city of Utrecht, the Netherlands. Results on stage at diagnosis, case-fatality, and mortality rates suggest that the program has been effective. Attention is devoted to the issue whether knowledge about risk factors for breast cancer is helpful in making a screening program more effective or efficient. It is concluded that such knowledge is of limited importance.