[Organized breast cancer screening].

Breast screening programs are increasingly controversial, especially regarding two points: the number of breast cancer deaths they avoid, and the problem of over-diagnosis and over-treatment. The French national breast cancer screening program was extended to cover the whole country in 2004. Ten years later it is time to examine the risk/benefit ratio of this program and to discuss the need for change. Like all forms of cancer management, screening must be regularly updated, taking into account the state of the art, new evidence, and uncertainties. All screening providers should keep themselves informed of the latest findings. In the French program, women aged 50-74 with no major individual or familial risk factors for breast cancer are offered screening mammography and clinical breast examination every two years. Images considered non suspicious of malignancy by a first reader are re-examined by a second reader. The devices and procedures are subjected to quality controls. Participating radiologists (both public and private) are required to read at least 500 mammographies per year. The program's national participation rate was 52.7 % in 2012. When individual screening outside of the national program is taken into account (nearly 15 % of women), coverage appears close to the European recommendation of 65 %. Breast cancer mortality has been falling in France by 0.6 % per year for over 30 years, starting before mass screening was implemented, and by 1.5 % since 2005. This decline can be attributed in part to earlier diagnosis and better treatment, so that the specific impact of screening cannot easily be measured. Over-treatment, defined as the detection and treatment of low-malignancy tumors that would otherwise not have been detected in a person's lifetime, is a major negative effect of screening, but its frequency is not precisely known (reported to range from 1 % to 30 %). In view of these uncertainties, it would be advisable to modify the program in order to increase its efficiency, by targeting populations at a higher risk than the women currently included, and to reduce the number of mammograms done outside the program, as they are not subject to the same quality controls. Risks could be reduced by increasing the sensitivity of mammography and the specificity of the readings. Moreover, it is mandatory to inform women of both the benefits and risks of screening, in compliance with the principle of enabling patients to make a free and informed choice.