A cohort study from the Friuli Venezia Giulia region

Few healthcare interventions have been as controversial as mammography screening for breast cancer (BC). Both in the scientific and lay press, the so-called ‘screening controversy’ has surrounded two main issues; namely, the validity of randomised controlled trials (RCTs) conducted in the 1970s and 1980s, supposedly affected by flaws in randomisation and ascertainment of the causes of death; and the quality and effectiveness of the more recently implemented public health organised screening programmes (SP).

Regarding organised screening programmes, it has been argued that they cannot have the same theoretical level of effectiveness as RCTs because they involve a wider base of professionals who are less experienced and less motivated. Moreover, SPs are superimposed on a background of long-term quality improvements in BC treatment, with a decrease in the relative benefits of early detection. Finally, more attention has been placed on the anxiety and inconvenience caused by false-positive mammography results and on the occurrence of overdiagnosis.

To respond to these problems, the emphasis for screening evaluation has shifted from the results of historical RCTs to those of screening activities organised by public health organisations. After the publication of the comprehensive literature reviews conducted by the EUROSCREEN Working Group, observational studies have been recognised as the main contributors of data on the impact of BC screening as a public health measure.

In Italy, the availability of observational studies of the effectiveness of local and regional screening programmes is still limited: two studies of mortality trends and an incidence-based mortality study were conducted in a single region and in a single province. A fourth mortality study (case-control design), covered several districts situated in five regions. Parts of these regions were also targeted by a study of trends in advanced-stage BC incidence, an endpoint not taken into consideration for the EUROSCREEN reviews. When the authors of this study proposed a cohort study of cumulative incidence of advanced BC according to participation in a screening programme, (approach recommended by the EUROSCREEN group) only a minority of screening services in three regions contributed their data.

I have conducted a retrospective cohort study aimed at comparing the incidence rates of advanced BC (herein defined as size T2 or more, lymph-node positive, or TNM stage II or more) between participants and non-participants in the Friuli-Venezia Giulia (FVG) Region mammography screening programme.

Age-standardised incidence rate (per 100,000) of invasive BC by exposure to mammography screening in FVG and year of FU.

This study has been the first to evaluate the effectiveness of a region-wide mammography SP implemented in Italy since 2000. This study was conducted in line with the recommendation from the EUROCOURSE group to improve the interface between SP and cancer registries. This study has provided a unique opportunity to assess the efficiency of an information system that collects both the mammography screening records and the cancer registry records from multiple healthcare districts. In Italy, so far, a record linkage between individual mammography screening records and cancer registry records has never been performed on a regional basis.

Moreover, this work brought together the recommendations from the European Society of Breast Cancer Specialists (EUSOMA) for the creation of a data management unit within specialist breast units and for the integration of these and mammography SPs. We showed that attendance of the FVG mammography screening programme in the first years of operation was associated with a significant decrease in the risk of advanced BC that was independent of self-selection biases. The information system assembled for this study has been made available to the FVG regional Department of Health for future replications of the study. This will provide more precise estimates of the impact of the programme and will enable monitoring of the effects of the transformations currently under way in the local health service.

Fabiola Giudici is a Biostatistician PhD student studying Experimental and Translational Medicine at the Unit of Biostatistics, Epidemiology and Public Health of Padua University. She is Data Manager of the Trieste Breast Unit ASUITS.

Research Presentation Session
RPS 502 Breast cancer screening scenarios with and without tomosynthesis

The early effects of a mammography screening programme on advanced breast cancer incidence in the Friuli Venezia Giulia Italian region
F. Giudici1, M. Tonutti1, M. Bortul1, F. Zanconati1, A. Zucchetto2, A. Franzo3, M. Gobbato3, M. A. Cova1, L. Bucchi4; 1Trieste /IT, 2Cro-Aviano/IT, 3Udine/IT, 4Forlì-Meldola/IT

Read the full abstract in the ECR 2020 Book of Abstracts
Giudici F, et al. (2020) The early effects of a mammography screening programme on advanced breast cancer incidence in the Friuli Venezia Giulia Italian region. Abstract RPS 502-4 in: ECR 2020 Book of Abstracts. Insights Imaging 11, 34 (2020). DOI 10.1186/s13244-020-00851-0