False-Positive Results in Mammographic Screening for Breast Cancer in Europe: A Literature Review and Survey of Service Screening Programmes

Abstract

Objective To estimate the cumulative risk of a false-positive screening result in European mammographic screening programmes, and examine the rates and procedures of further assessment. Methods A literature review was conducted to identify studies of the cumulative risk of a false-positive result in European screening programmes (390,000 women). We then examined aggregate data, cross-sectional information about further assessment procedures among women with positive results in 20 mammographic screening programmes from 17 countries (1.7 million initial screens, 5.9 million subsequent screens), collected by the European Network for Information on Cancer project (EUNICE). Results The estimated cumulative risk of a false-positive screening result in women aged 50-69 undergoing 10 biennial screening tests varied from 8% to 21% in the three studies examined (pooled estimate 19.7%). The cumulative risk of an invasive procedure with benign outcome ranged from 1.8% to 6.3% (pooled estimate 2.9%). The risk of undergoing surgical intervention with benign outcome was 0.9% (one study only). From the EUNICE project, the proportions of all screening examinations in the programmes resulting in needle biopsy were 2.2% and 1.1% for initial and subsequent screens, respectively, though the rates differed between countries; the corresponding rates of surgical interventions among women without breast cancer were 0.19% and 0.07%. Conclusion The specific investigative procedures following a recall should be considered when examining the cumulative risk of a false-positive screening result. Most women with a positive screening test undergo a non-invasive assessment procedure. Only a small proportion of recalled women undergo needle biopsy, and even fewer undergo surgical intervention.

A retrospective audit of the first screening round of the Maltese breast screening programme

“…43, 50. A TR rate of 0.26% indicated high image quality locally, as the objective of a screening programme is to minimise the number of women undergoing technical recalls while achieving the optimum image quality. 20 To obtain such an excellent TR Rate careful selection and training of staff is necessary.…”

“…Therefore only new findings would be fully investigated, thus lowering recall rates and further increasing PPV. 28,20 …”

“…4 Previous research states that recall rates were influenced by several factors including training and experience of radiologists, image quality, the volume of mammograms interpreted and the age of screened women. 19,20,21 Early Recall Rate ER was found to be associated with a low predictive value for malignancy and thus every effort should be made to obtain a definitive diagnosis at initial assessment. 4,22,23,24 Additionally, a study analysing 110 women who were recalled early, revealed that 3.6% had invasive cancer, 0.9% had DCIS, while 84% had benign findings.…”

“…33 This was reasonable given the relatively higher breast density and lower incidence of disease in younger women. 34,20 Alternatively, studies analysing cohorts of women undergoing successive screening rounds indicated no clear association between age and risks of false-positive mammograms, concluding that such risks are much higher in first screening rounds. 35,36 Nevertheless, there were no considerable reductions from second rounds onwards, regardless of women's increasing age.…”

“…A TR rate of 0.26% indicated high image quality locally, as the objective of a screening programme is to minimise the number of women undergoing technical recalls while achieving the optimum image quality. 20 To obtain such an excellent TR Rate careful selection and training of staff is necessary.Low predictive value for malignancy in ER has been expressed in various studies 24,25 being consistent with this study's findings as the majority of cancers were detected at initial screen, with only 2 cancers detected at ER stage. Nevertheless the latter could represent late diagnosis and failure of the screening and assessment process since women were falsely reassured, and ultimately diagnosed with cancer.…”