Extrapolation of pre-screening trends: Impact of assumptions on overdiagnosis estimates by mammographic screening

Background: Overdiagnosis by mammographic screening is defined as the excess in breast cancer incidence in the presence of screening compared to the incidence in the absence of screening. The latter is often estimated by extrapolating the pre-screening incidence trend. The aim of this theoretical study is to investigate the impact of assumptions in extrapolating the pre-screening incidence trend of invasive breast cancer on the estimated percentage of overdiagnosis. Methods: We extracted data on invasive breast cancer incidence and person-years by calendar year (1975-2009) and 5-year age groups (0-85 years) from Dutch databases. Different combinations of assumptions for extrapolating the pre-screening period were investigated, such as variations in the type of regre

Impact of mammographic screening and advanced cancer definition on the percentage of advanced-stage cancers in a steady-state breast screening programme in the Netherlands

Background: To estimate the percentages of advanced-stage breast cancers (BCs) detected during the course of a steady-state screening programme when using different definitions of advanced BC. Methods: Data of women aged 49–74 years, diagnosed with BC in 2006–2015, were selected from the Netherlands Cancer Registry and linked to the screening registry. BCs were classified as screen-detected, interval or non-screened. Three definitions of advanced BC were used for comparison: TNM stage (III–IV), NM stage (N+ and/or M+) and T size (invasive tumour ≥15 mm). Analyses were performed assuming a 10% overdiagnosis rate. In sensitivity analyses, this assumption varied from 0 to 30%. Results: We included 46,734 screen-detected, 17,362 interval and 24,189 non-screened BCs. By TNM stage, 4.9% of screen-detected BCs were advanced, compared with 19.4% and 22.8% of interval and non-screened BCs, respectively (p < 0.001). Applying the other definitions led to higher percentages of advanced BC being detected. Depending on the definition interval, non-screened BCs had a 2–5-times risk of being advanced. Conclusion: Irrespective of the definition, screen-detected BCs were less frequently in the advanced stage. These findings provide evidence of a stage shift to early detection and support the potential of mammographic screening to reduce treatment-related burdens and the mortality associated with BC

Deep learning-based breast region segmentation in raw and processed digital mammograms:generalization across views and vendors

Purpose: We developed a segmentation method suited for both raw (for processing) and processed (for presentation) digital mammograms (DMs) that is designed to generalize across images acquired with systems from different vendors and across the two standard screening views. Approach: A U-Net was trained to segment mammograms into background, breast, and pectoral muscle. Eight different datasets, including two previously published public sets and six sets of DMs from as many different vendors, were used, totaling 322 screen film mammograms (SFMs) and 4251 DMs (2821 raw/processed pairs and 1430 only processed) from 1077 different women. Three experiments were done: first training on all SFM and processed images, second also including all raw images in training, and finally testing vendor generalization by leaving one dataset out at a time. Results: The model trained on SFM and processed mammograms achieved a good overall performance regardless of projection and vendor, with a mean (±std. dev.) dice score of 0.96 0.06 for all datasets combined. When raw images were included in training, the mean (±std. dev.) dice score for the raw images was 0.95 0.05 and for the processed images was 0.96 0.04. Testing on a dataset with processed DMs from a vendor that was excluded from training resulted in a difference in mean dice varying between −0.23 to þ0.02 from that of the fully trained model. Conclusions: The proposed segmentation method yields accurate overall segmentation results for both raw and processed mammograms independent of view and vendor. The code and model weights are made available.</p

European guidelines for quality assurance in breast cancer screening and diagnosis. Fourth edition - summary document

Rak piersi jest najczęstszą przyczyna zgonu wśród kobiet i stanowi istotny problem kliniczny. Wczesne wykrycie raka piersi dzięki regularnie prowadzonym badaniom przesiewowym za pomocą mammografii umożliwia rozpoznanie choroby w stadium, w którym leczenie jest skuteczniejsze i zazwyczaj wiąże się z lepszą jakością życia. Jednakże mammografia może być przyczyną niepotrzebnego stresu, dolegliwości, kosztów finansowych oraz narażenia na promieniowanie jonizujące. Z tego powodu należy położyć możliwie największy nacisk na kontrolę jakości. Opracowanie Europejskich zaleceń dotyczących kontroli jakości badań przesiewowych i rozpoznawania raka piersi było inicjatywą programu Europa przeciwko rakowi. Czwartą edycję interdyscyplinarnych zaleceń opublikowano w 2006 roku. Składa się z około 400 stron podzielonych na 12 rozdziałów przygotowanych przez ponad 200 autorów i współautorów. Interdyscyplinarna rada wydawnicza przygotowała streszczenie dokumentu w celu przedstawienia podstawowych zasad i założeń, na których powinny opierać się badania przesiewowe oraz diagnostyka raka piersi. Opracowanie zawiera także tabelę podsumowującą wskaźniki wydajności, aby szersze grono naukowców mogło się z nią zapoznać.Breast cancer is a major cause of suffering and death and is of significant concern to many women. Early detection of breast cancer by systematic mammography screening can find lesions for which treatment is more effective and generally more favourable for quality of life. The potential harm caused by mammography includes the creation of unnecessary anxiety and morbidity, inappropriate economic cost and the use of ionising radiation. It is for this reason that the strongest possible emphasis on quality control and zmniejquality assurance is required. Development of the European Guidelines for Quality Assurance in Breast Cancer Screening and Diagnosis has been an initiative within the Europe Against Cancer Programme. The fourth edition of the multidisciplinary guidelines was published in 2006 and comprises 400 pages divided into 12 chapters prepared by >200 authors and contributors. The multidisciplinary editorial board has prepared a summary document to provide an overview of the fundamental points and principles that should support any quality screening or diagnostic service. This document includes a summary table of key performance indicators and is presented here in order to make these principles and standards known to a wider scientific communit

Consequences of digital mammography in population-based breast cancer screening: initial changes and long-term impact on referral rates

Contains fulltext : 89208.pdf (publisher's version ) (Closed access)OBJECTIVES: To investigate the referral pattern after the transition to full-field digital mammography (FFDM) in a population-based breast cancer screening programme. METHODS: Preceding the nationwide digitalisation of the Dutch screening programme, an FFDM feasibility study was conducted. Detection and referral rates for FFDM and screen-film mammography (SFM) were compared for first and subsequent screens. Furthermore, radiological characteristics of referrals in digital screening were assessed. RESULTS: A total of 312,414 screening mammograms were performed (43,913 digital and 268,501 conventional), with 4,473 consecutive referrals (966 following FFDM). Initially the FFDM referral rate peaked, and many false-positive results were noted as a consequence of pseudolesions and increased detection of (benign) microcalcifications. A higher overall referral rate was observed in FFDM screening in both first and subsequent examinations (p < .001), with a significant increase in cancer detection (p = .010). CONCLUSION: As a result of initial inexperience with digital screening images implementing FFDM in a population-based breast cancer screening programme may lead to a strong, but temporary increase in referral. Dedicated training in digital screening for radiographers and screening radiologists is therefore recommended. Referral rates decrease and stabilise (learning curve effect) at a higher level than in conventional screening, yet with significantly enhanced cancer detection.1 september 201

Создание развитых интернет-программ на примере построения виджет-программ

Рассмотрено применение методологии создания развитых Интернет-программ на основе Adobe Flex 2.0 с применением паттернов проектирования и архитектурного каркаса. Подход проиллюстрирован построением виджет-программ

The dilemma of recalling well-circumscribed masses in a screening population: A narrative literature review and exploration of Dutch screening practice

Background: In Dutch breast cancer screening, solitary, new or growing well-circumscribed masses should be recalled for further assessment. This results in cancers detected but also in false positive recalls, especially at initial screening. The aim of this study was to determine characteristics of well-circumscribed masses at mammography and identify potential methods to improve the recall strategy. Methods: A systematic literature search was performed using PubMed. In addition, follow-up data were retrieved on all 8860 recalled women in a Dutch screening region from 2014 to 2019. Results: Based on 15 articles identified in the literature search, we found that probably benign well-circumscribed masses that were kept under surveillance had a positive predictive value (PPV) of 0–2%. New or enlarging solitary well-circumscribed masses had a PPV of 10–12%. In general the detected carcinomas had a favorable prognosis. In our exploration of screening practice, 25% of recalls (2133/8860) were triggered by a well-circumscribed mass. Those recalls had a PPV of 2.0% for initial and 10.6% for subsequent screening. Most detected carcinomas had a favorable prognosis as well. Conclusion: To recognize malignancies presenting as well-circumscribed masses, identifying solitary, new or growing lesions is key. This information is missing at initial screening since prior examinations are not available, leading to a low PPV. Access to prior clinical examinations may therefore improve this PPV. In addition, given the generally favorable prognosis of screen-detected malignant well-circumscribed masses, one may opt to recall these lesions at subsequent screening, if grown, rather than at initial screening