Further evidence of benefits of a (non-randomised) breast cancer screening programme: the DOM project.

Abstract

Study objective-The aim was to demonstrate the benefits of breast cancer screening on mortality.Design-The study was an evaluation of a breast cancer screening programme by means of different approaches: (1) a casecontrol study, breast cancer deaths being the cases; (2) comparing the numbers of breast cancer deaths in screened and unscreened women; (3) comparing breast cancer mortality before and after start of the programme; (4) comparing breast cancer mortality in different large cities; (5) comparing screening activity with mortality reduction.Setting-The setting was a breast cancer screening programme in the city ofUtrecht, the DOM project, for women aged 50-64 years old at intake, birth cohort 1911-1925 The first effects on mortality from breast cancer of a mass screening project in the city of Utrecht using both physical examination and (xero)mammography were published in 1984.' The project was called the DOM project, which in Dutch signifies "Diagnostisch Onderzoek (= investigation) Mammacarcinoom". It has a double meaning, because Utrecht is sometimes called the DOM city for its medieval cathedral. As the DOM project used a non-randomised design, we measured the effects on mortality from breast cancer by means of a case controlled study.In the case-control study, a case was defined as a breast cancer death in a woman born between 1911 and 1925, diagnosis and death occurring after the start of the project. For each case, three controls were selected at random from the local population registries, matched for year of birth. For both the case and the corresponding controls, the screening history was ascertained from the records of the DOM project. The screening history was taken for the time up to and including the date of diagnosis of the case, ie, a "restricted period" compared with the period of the total screening programme. A protective effect of screening against dying from breast cancer was found (odds ratio 0 30, 95% confidence interval 0 13-070).No biasing factors were found: in particular the incidence rate of breast cancer in the unscreened group was the same as in the population before the start of the project and the stage of the tumours did not much differ either.2 There were no changes in therapy in that period.Although this was not the first time that a screening project had been evaluated by means of a case-control approach,3 and at the same time a screening programme in Nijmegen was evaluated in the same way4 and others followed as well,5 some criticisms have been raised. Therefore we felt it desirable, in addition to updating the case-control study and searching further for confounding variables, to use alternative approaches to the evaluation of the screening effect. This paper includes: (1) an update of the case-control study (odds ratio) and further search for confounding factors; (2)

Impact of Screening on Breast Cancer Mortality: The UK Program 20 Years On

“…In agreement with our results, other case-control studies have reported increased benefit with number of screens, and decreased benefit with increasing time since last breast screen, that is, in the United Kingdom (28,30) and in early (prior to 1990) studies set up in Utrecht, the Netherlands (36,37).…”

Seventeen-year evaluation of breast cancer screening: the DOM project, The Netherlands

“…A higher lexel of protection in older women has been described earlier in the DOM project (Collette et al 1984(Collette et al . 1985(Collette et al . 1992 and in other studies (Tabar et al 1995).…”

“…local authorities and the Central Bureau for Statistics (CBS) ensured the followi-up of the invited A-omen. More detailed information about the screening design has been described prexiously (Collette et al 1984. 1992 (Weiss and Lazovich.…”

Efficacy of Screening Mammography

“…We also com¬ bined RRs and ORs to evaluate the ef¬ fect of the number of mammographie views performed per screen, screening interval, and duration of follow-up and to assess the benefit of clinical breast examination performed in conjunction with mammographie screening. METHODS A comprehensive literature search of English-language studies from January Follow-up, y Edinburgh 4,9,24 1979 45-64 RCT* 24 2 § Yes 10 Malmo 3, 8,9 1976 45-69 RCT [18][19][20][21][22][23][24] years. Separate summary RR estimates were also calculated for experimental vs nonexperimental studies.…”