The French organized breast cancer screening program invites women aged 50 to 74 to undergo a clinical breast exam and a screening mammogram every two years. It offers immediate diagnostic evaluation in the event of suspicious results and a second reading of every mammogram that is initially deemed normal. The program was expanded to cover the entire French territory in 2004. Screening is coordinated at the regional level by the Regional Cancer Screening Coordination Centers (CRCDC). Participation rates for this program, calculated for the years 2005 through 2019, are presented below at the national, departmental, and regional levels.

Materials and Methods

The number of women screened is reported to Santé publique France in February–March of each year by the CRCDCs using a standardized annual questionnaire. The data received are aggregated by 5-year age groups. The 50–54 age group includes screened women who turned 50 during the year under review, even if they had not reached that age at the time of screening; the 70–74 age group includes women who had turned 75 at the time of screening, generally due to a delay in undergoing the mammogram after receiving the invitation sent up to age 74.

At the national level and for the purpose of comparing regions and departments, the denominators used to calculate participation rates are the localized population estimates (ELP) from INSEE. Each year, INSEE estimates the population of regions and departments (metropolitan France and the overseas departments and regions) as of January 1. These annual population estimates are available by sex, age, and department. The estimates provided are based on the latest population censuses, statistical analysis of civil registry records, and several other administrative sources. They were used to calculate the target screening populations by age group. Since there is no consistent data over time and across regions, exclusions from screening for medical or family reasons are not deducted from the denominator.

The participation rate is calculated for each calendar year on the one hand and for each two-year period on the other. Indeed, the number of women screened during a given year may be influenced by invitation strategies, particularly in the early years of the program’s implementation. Rates calculated over two years allow for a period during which the entire target population should have been invited and thus better reflect women’s participation. In 2004, some departments had not yet completed a full year of invitations, and certain overseas departments did not implement this program until 2005. The results are therefore presented starting in 2005.

Both crude and age-standardized participation rates are presented. They are calculated by age group, by department, by region, and for France as a whole. The age-standardized rates (using the 2009 French population as the reference population, based on the INSEE Omphale projection for 2007–2042, central scenario) allow for comparisons between regions and over time.

Results

Results for the 2018–2019 period and trends in national and age-specific participation

In 2019, 2,551,000 women underwent screening, corresponding to a national participation rate of 48.6% (see table under the “Annual” tab). For the 2018–2019 period, the participation rate is 49.3% (see table under the “Biennial” tab). All annual and biennial standardized rates are available here.

The figure shows the trend in national participation, for all ages and by age group. After increasing through 2011–2012 to reach a peak of 52.4%, participation in the program has been declining. The latest participation indicators for the 2018–2019 period indicate that this decline is continuing slowly. This decline is observed across all age groups and is particularly pronounced among those aged 55–59, who have the lowest participation rate.

Trends in Participation by Region and Department

The figure shows the trend in participation by metropolitan region and for the DROMs; the tables on gross participation (2005–2019) and standardized participation (2005–2019) provide annual and biennial participation figures by region, and the table on participation by age group (2005–2019) describes the trend in participation by age in each region.

The decline observed at the national level is also evident in most regions of metropolitan France, primarily in those that previously had the highest turnout, namely Centre-Val de Loire and Pays de la Loire. Conversely, participation has remained flat in regions with very low participation rates, namely Île-de-France, Corsica, and PACA. In the overseas departments and regions (DROM), significant declines have been observed, particularly in French Guiana, where, for example, participation in 2019 was only 21.8%.

Geographical variation in voter turnout, by region and department

One consequence of the differing trends from one region to another is that the heterogeneity in turnout across the country observed in previous years has decreased significantly for the 2018–2019 period, with regional differences ranging from 35.2% in Corsica and 38.4% in Île-de-France to 56.4% in Pays de la Loire and 57.1% in Centre-Val de Loire (see graph). In the overseas territories, rates range from 23.1% in French Guiana to 46.5% in Réunion and Guadeloupe. This reduction in geographic heterogeneity is also observed at the departmental level, with a less pronounced east-west gradient than in previous years (see table on crude and standardized participation rates and maps).

Conclusion

Possible explanations for the decline in participation observed starting in 2011–2012 include the controversy over the benefits and risks of breast cancer screening, and a decrease in breast care services. These hypotheses, as well as their varying impact across regions—particularly in those where participation was highest—should be studied. It would also be advisable to study what is happening in the overseas regions.

Furthermore, it is necessary to have tools to accurately measure the uptake of individual screening in order to (1) describe any potential shifts between organized and individual screening, and (2) track overall trends in breast cancer screening uptake. Work currently being finalized by the Agency to estimate individual screening based on the SNDS (National Health Data System) should make it possible to document these aspects in the short term, but specific coding of individual screening procedures is necessary to facilitate their identification.