Breast cancer is the most common cancer among women. The prognosis is all the more favorable when the disease is detected at an early stage. Various targeted international studies have concluded that, provided implementation conditions combine methodological rigor with technical quality, organized screening reduces the risk of breast cancer mortality by 30% among women aged 50 to 69 who undergo regular screening... The program’s effectiveness is measured in terms of the reduction in breast cancer mortality among the screened population. Some time is needed to obtain these data. Early indicators, recommended by the Europe Against Cancer program, are therefore used to monitor the program’s impact, quality, and effectiveness. This article presents the results of the epidemiological follow-up of the national program through the end of December 1997. (R.A.)