Mammography Screening - as of 2013

Abstract

Introduction: Since 2008 the German Mammography Screening Programme has been available throughout Germany to all women aged between 50 and 69. The programme strictly follows the European Guidelines. There are controversial discussions in the media as well as in the specialised press. Materials and Methods: Overview of the available data with regard to an evaluation of randomised studies and with regard to quality-assured screening programmes in accordance with EU Guidelines (including data from 18 screening countries). Results: Positive effects of screening: reduction in mortality, less invasive treatment. Negative effects: False-positive diagnoses and biopsy recommendations, so-called overdiagnoses, radiation dose. Limits of screening: Interval carcinomas, incomplete reduction in mortality. A mathematical synopsis of the latest publications from the European screening programmes with the diagnosis rates in Germany determined from > 4.6 million screening examinations produces the following: a total of 10 000 mammograms are created for 1000 women (P) taking part in the Mammography Screening Programme (each of whom undergoes 10 mammograms in 20 years). Overall, the risk of triggering breast cancer through a mammogram is very clearly below the annual natural risk of suffering from breast cancer. In the German screening, of these 1000 women, an average of 288 women are called back once in 20 years as a result of changes that are ultimately benign (< 3 % per cycle). Of these, 74 of the 288 women undergo a biopsy due to a benign change (false-positive biopsy recommendations, usually punch or vacuum biopsies). According to EUROSCREEN, 71 carcinomas develop among participants (56 are discovered in the screening, 15 in the interval), and 67 carcinomas among non-participants (N-P) (in some cases, several years later) during this period. The 4 additional diagnoses among the Ps are referred to as overdiagnoses, as they do not contribute to a reduction in mortality (these participants die beforehand from other causes of death). With regard to the carcinomas that concern the screening periods, 11 women out of 1000 die among the Ps; there are 19 deaths among the N-Ps (within the observation period plus follow-up period). Discussion: The false-positive rate is unavoidable, but is far lower with mammography screening than with other methods. Overdiagnoses are to be expected with any early detection. All calculations require assumptions and are therefore highly discrepant. They have very low evidence levels. The radiation dose should not be an argument against screening when applied correctly due to the very low risk and significant benefits. Interval carcinomas indicate the limits of a mammography screening programme. False-negatives only represent a subset of the interval carcinomas and are not to be equated with them. There is a very high evidence level for a significant reduction in mortality through mammography screening. For the first time, an independent expert commission has confirmed the results of the randomised studies and the statement of the WHO from 2002 and their further validity. Participants can expect a reduction in mortality of 30 %. Data from the current European screening programmes confirm a mortality reduction of 43 %, corresponding to 8/19 saved lives among 71 women with breast cancer or 1000 asymptomatic Ps. Many additional Ps benefit from less invasive treatment due to the early detection. Conclusions: As a result of the risk/benefit ratio, mammography screening should absolutely be recommended to asymptomatic women aged between 50-69. High importance is given to the provision of education for women by the treating gynaecologists as regards the opportunities for quality-assured early detection available to them in the healthcare system.

Keywords: breast cancer; mamma; mammogram screening.

Fig. 1

Simple T-stage distribution of invasive breast cancers in the screening (2005–2007, 2008–2009) and in the target population (2000–2005). There is a noticeable increase in small invasive carcinomas in the screened population .

Fig. 2

Proportion of lymph node-negative carcinomas in the screening (2005–2007, 2008–2009) and in the target population (2000–2005). The effect of the screening can already be seen at the beginning of the programme: an increase in node-negative carcinomas with a simultaneous reduction in node-positive carcinomas in the screened women .