Participation rates in the organized breast cancer screening program for 2021–2022 and trends since 2005

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 has been available nationwide in France since 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 2021, 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 in a standardized data format, aggregated by 5-year age groups. The 50–54 age group includes women who turned 50 during the year under review, even if they had not yet 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 INSEE’s localized population estimates (ELP). 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 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. In the absence of comparable data over time and across different 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, not all departments were able to participate in a full year of screening, and some 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

The tables, figures, and map describing temporal and geographic variations for the period 2005–2022 are available for download at the bottom of the page.

Temporal Trends

The national participation rate for the 2021–2022 period is 47.7%, or 50.5% for 2021 and 44.9% for 2022.

After rising through 2011–2012 to peak at 52.3%, participation in the program has been declining for the past 10 years across all age groups and regions. In 2020, due to the first lockdown and the closure of CRCDC centers, the participation rate dropped significantly, both overall and across all age groups and departments. The year 2021 showed a recovery across all age groups and all departments, reflecting increased activity at CRCDCs and radiology practices to offset the decline in 2020. In 2022, participation was lower than in 2021. It remains slightly lower than in 2019 across all age groups and the vast majority of departments.

Since women are invited every two years for mammography screening, it is important to examine the data over rolling two-year periods. We then observe that participation in the 2021–2022 period remains lower than participation in 2018–2019 for the vast majority of departments and regions.

The suspension of invitations by the CRCDC and the closure of radiology practices in 2020 caused delays in the invitation cycles. In 2021, the CRCDC informed us that they had to reorganize to stagger the sending of invitations so as not to overwhelm radiology practices and to be able to schedule second readings. They adjusted their invitation schedules, for example by shortening the originally planned interval for inviting non-participants following the previous invitation, or by slightly shifting the originally scheduled dates for follow-up reminders, … Despite this, the volume of invitations increased, leading to delays in scheduling appointments at radiology clinics and, consequently, in performing mammograms. Based on observations over a two-year period, it appears that participation is on the rise again, but it is likely that the consequences of the disruptions caused by COVID-19 will not fully subside for another four or five years and will continue to impact the organization of invitations and the calculation of participation rates. It should be noted that the gradual decline in breast care services is already causing difficulties in scheduling appointments [1]. A gradual increase in the time between mammograms has also been observed in recent years [2].

Temporal trends in participation are relatively similar across regions, with the exception of French Guiana. In this territory, a concerning decline has been observed since 2016.

Geographic Variations

Participation for the 2021–2022 period ranges from 21.2% in French Guiana to 55.3% in the Pays de la Loire region. A geographic gradient is observed across mainland France: the highest participation is observed in the Pays de la Loire region. Very low participation is observed in Île-de-France, the Southeast, and Corsica. It should be noted that our research has shown that these regions have a high level of individual (“opportunistic”) screening [3,4].

Participation by department for the year 2022 ranges from 13.5% in French Guiana to 57.0% in Maine-et-Loire.

Conclusion

In 2022, the breast cancer screening participation rate was lower than in the previous year, but 2021 was a year of catching up on the deficit observed in 2020 due to the COVID-19 pandemic and lockdowns. Based on observations over two-year periods, it appears that participation in 2021–2022 is beginning to rise. However, it is likely that the consequences of COVID-related disruptions will not fully subside for several years, while the gradual decline in breast cancer screening services was already leading to longer intervals between screenings. As a reminder, organized screening represents only a portion of screening practices in France, and some women undergo screening outside of the recommendations [3]. In the absence of a specific code to identify mammograms performed as part of individual screening within the SNDS, estimates of off-program practices remain imprecise.

Tables to download

Figures to download

Downloadable map

References

1. Gautier CP, Brousse-Potocki J, Quertier MC. Factors influencing the interval between two screening mammograms. 42nd SFSPM Conference, Nice, November 9, 2022.
2. Plaine J, Quintin C, Rogel A. Intervals between two organized screening mammograms. 42nd SFSPM Conference, Nice, November 9, 2022.
3. Quintin C, Chatignoux E, Plaine J, Hamers FF, Rogel A. Coverage rate of opportunistic and organized breast cancer screening in France: Department-level estimation. Cancer Epidemiol. 2022 Oct 7;81:102270. doi:10.1016/j.canep.2022.102270.
4. Rogel A, Plaine J, Quintin C. Opportunistic breast cancer screening: estimates and trends. 42nd SFSPM Conference, Nice, November 9, 2022.