Evaluation of service screening mammography in practice: the impact on breast cancer mortality

A Multireader Multicase (MRMC) Receiver Operating Characteristic (ROC) Study Evaluating Noninferiority of Quantitative Transmission (QT) Ultrasound to Digital Breast Tomosynthesis (DBT) on Detection and Recall of Breast Lesions

RATIONALE AND OBJECTIVES

Quantitative transmission (QT) imaging is an emerging volumetric ultrasound modality for women too young for mammography. QT images tissue without overlap seen in mammography, thereby can potentially improve breast mass detection and characterization and noncancer recall. We compared radiologists' interpretation of QT vs digital breast tomosynthesis (DBT) with a multireader multicase observer performance study.

MATERIALS AND METHODS

Study subjects received screening DBT and QT scans in HIPAA-compliant, institutional review board-approved prospective case-collection studies at four clinical sites. Twenty-four Mammography Quality Standards Act-qualified radiologists interpreted 177 cases (66 with cancer, atypia, or solid mass and 111 normal or with nonsolid benign abnormality), first QT, then 2 weeks later DBT synthesized 2D-views. Readers reported up to three findings per case and for each finding a recall or no recall decision and confidence of that decision. The study hypothesis was area under receiver operating characteristic curve (AUC) of QT was noninferior to DBT. Sensitivity and specificity were also compared.

RESULTS

AUC of QT (0.746 ± 0.028, mean ± SD) was noninferior to DBT (0.700 ± 0.028) for AUC difference margin of -0.05 (P < .05). AUC difference was 0.046 ± 0.028 (95% CI: [-0.008, 0.101]). Sensitivity was 70.6 ± 7.2% for QT and 85.2 ± 6.4% for DBT, specificity was 60.1 ± 12.3% vs 37.2 ± 11.0%, and both differences were statistically significant. Of a total of 21 cases of cysts, readers recommended recall, on average, in 1.1 ± 1.4 cases with QT, but not with DBT, and 10.6 ± 2.2 cases with DBT, but not with QT.

CONCLUSION

QT can be a potential alternative to mammography for breast cancer screening of women too young to undergo mammography.

Unsupervised anomaly detection with generative adversarial networks in mammography

Breast cancer is a common cancer among women, and screening mammography is the primary tool for diagnosing this condition. Recent advancements in deep-learning technologies have triggered the implementation of research studies via mammography. Semi-supervised or unsupervised methods are often used to overcome the limitations of supervised learning, such as manpower and time, for labeling in clinical situations where abnormal data are significantly lacking. Accordingly, we proposed a generative model that uses a state-of-the-art generative network (StyleGAN2) to create high-quality synthetic mammographic images and an anomaly detection method to detect breast cancer on mammograms in unsupervised methods. The generation model was trained via only normal mammograms and breast cancer classification was performed via anomaly detection using 50 breast cancer and 50 normal mammograms that did not overlap with the dataset for generative model learning. Our generative model has shown comparable fidelity to real images, and the anomaly detection method via this generative model showed high sensitivity, demonstrating its potential for breast cancer screening. This method could differentiate between normal and cancer-positive mammogram and help overcome the weakness of current supervised methods.

Leveraging breast cancer screening to promote timely detection, diagnosis and treatment among women in sub-Saharan Africa: a scoping review protocol

INTRODUCTION

Female breast cancer is now the most often diagnosed cancer in the world. Breast cancer screening aims to reduce mortalities related to cancer, and morbidity associated with advanced stages of the disease, through timely detection in asymptomatic women. This study aims to conduct a comprehensive assessment and evaluation of the evidence on the factors that influence the provision and uptake of breast cancer screening among women in sub-Saharan Africa (SSA).

METHODS AND ANALYSIS

PubMed, Web of Science, EMBASE and the Cumulative Index to Nursing and Allied Health Literature including Google Scholar will be searched to identify published studies on barriers and facilitators to breast cancer screening from January 2010 to 2021. Two reviewers will independently assess the quality of all the included studies using the Mixed Methods Appraisal Tool version 2018. We envisage that this review will adduce evidence on common barriers and facilitators to breast cancer screening in SSA. Identifying these barriers and facilitators will help guide the initialisation of effective interventions that will improve breast cancer screening uptake among women in SSA. This review will also guide future research in developing, implementing and evaluating appropriate interventions tailored toward increasing breast cancer screening uptake.

ETHICS AND DISSEMINATION

Ethics approval for this protocol is not required since it does not involve collecting data from human participants. The outcomes of this study will be published in a peer-reviewed journal.

Prevalence and determinants of breast cancer screening in four sub-Saharan African countries: a population-based study

OBJECTIVES

Breast cancer is the most prevalent cancer and the second leading cause of cancer-related deaths among women after cervical cancer in much of sub-Saharan Africa. This study aims to examine the prevalence and sociodemographic-socioeconomic factors associated with breast cancer screening among women of reproductive age in sub-Saharan Africa.

DESIGN

A weighted population-based cross-sectional study using Demographic and Health Surveys (DHS) data. We used all available data on breast cancer screening from the DHS for four sub-Saharan African countries (Burkina Faso, Ivory Coast, Kenya and Namibia). Breast cancer screening was the outcome of interest for this study. Multivariable Poisson regression was used to identify independent factors associated with breast cancer screening.

SETTING

Four countries participating in the DHS from 2010 to 2014 with data on breast cancer screening.

PARTICIPANTS

Women of reproductive age 15-49 years (N=39 646).

RESULTS

The overall prevalence of breast cancer screening was only 12.9% during the study period, ranging from 5.2% in Ivory Coast to 23.1% in Namibia. Factors associated with breast cancer screening were secondary/higher education with adjusted prevalence ratio (adjusted PR)=2.33 (95% CI: 2.05 to 2.66) compared with no education; older participants, 35-49 years (adjusted PR=1.73, 95% CI : 1.56 to 1.91) compared with younger participants 15-24 years; health insurance coverage (adjusted PR=1.57, 95% CI: 1.47 to 1.68) compared with those with no health insurance and highest socioeconomic status (adjusted PR=1.33, 95% CI : 1.19 to 1.49) compared with lowest socioeconomic status.

CONCLUSION

Despite high breast cancer mortality rates in sub-Saharan Africa, the prevalence of breast cancer screening is substantially low and varies gradually across countries and in relation to factors such as education, age, health insurance coverage and household wealth index level. These results highlight the need for increased efforts to improve the uptake of breast cancer screening in sub-Saharan Africa.

Performance indicators in breast cancer screening in the European Union: A comparison across countries of screen positivity and detection rates

Comparable performance indicators for breast cancer screening in the European Union (EU) have not been previously reported. We estimated adjusted breast cancer screening positivity rate (PR) and detection rates (DR) to investigate variation across EU countries. For the age 50-69 years, the adjusted EU-pooled PR for initial screening was 8.9% (cross-programme variation range 3.2-19.5%) while DR of invasive cancers was 5.3/1,000 (range 3.8-7.4/1,000) and DR of ductal carcinoma in situ (DCIS) was 1.3/1,000 (range 0.7-2.7/1,000). For subsequent screening, the adjusted EU-pooled PR was 3.6% (range 1.4-8.4%), the DR was 4.0/1,000 (range 2.2-5.8/1,000) and 0.8/1,000 (range 0.5-1.3/1,000) for invasive and DCIS, respectively. Adjusted performance indicators showed remarkable heterogeneity, likely due to different background breast cancer risk and awareness between target populations, and also different screening protocols and organisation. Periodic reporting of the screening indicators permits comparison and evaluation of the screening activities between and within countries aiming to improve the quality and the outcomes of screening programmes. Cancer Screening Registries would be a milestone in this direction and EU Screening Reports provide a fundamental contribution to building them.

Breast-cancer mortality in screened versus unscreened women: Long-term results from a population-based study in Queensland, Australia

OBJECTIVE

In the context of a mature mammographic screening programme, the aim of this population-based study was to estimate rates of breast-cancer mortality among participants versus non-participants in Queensland, Australia.

METHODS

The Queensland Electoral Roll was used to identify women aged 50-65  in the year 2000 (n = 269,198). Women with a prior history of invasive or in situ breast cancer were excluded (n = 6,848). The study population was then linked to mammography records from BreastScreen Queensland together with the Wesley Breast Screening Clinic (the largest provider of private screening in Queensland) to establish a screened cohort (n = 187,558) and an unscreened cohort (n = 74,792). Cohort members were matched and linked to cancer notifications and deaths through the state-based Queensland Oncology Repository. Differences in breast-cancer mortality between the two cohorts were measured using Cox proportional hazards regression.

RESULTS

After 16 years of follow-up, women in the screened cohort showed a 39% reduction in breast-cancer mortality compared to the unscreened cohort (HR = 0.61, 95%CI = 0.55-0.68). Cumulative mortality over the same period was 0.47% and 0.77% in the screened and unscreened cohorts, respectively.

CONCLUSIONS

This study found a significant reduction in breast-cancer mortality for women who participated in mammographic screening compared to unscreened women. Our findings of a breast-cancer mortality benefit for women who have mammographic screening are in line with other observational studies.

A review of optical breast imaging: Multi-modality systems for breast cancer diagnosis

This review of optical breast imaging describes basic physical and system principles and summarizes technological evolution with a focus on multi-modality platforms and recent clinical trial results. Ultrasound-guided diffuse optical tomography and co-registered ultrasound and photoacoustic imaging systems are emphasized as models of state of the art optical technology that are most conducive to clinical translation.

Worldwide Review and Meta-Analysis of Cohort Studies Measuring the Effect of Mammography Screening Programmes on Incidence-Based Breast Cancer Mortality

In 2012, the Euroscreen project published a review of incidence-based mortality evaluations of breast cancer screening programmes. In this paper, we update this review to October 2019 and expand its scope from Europe to worldwide. We carried out a systematic review of incidence-based mortality studies of breast cancer screening programmes, and a meta-analysis of the estimated effects of both invitation to screening and attendance at screening, with adjustment for self-selection bias, on incidence-based mortality from breast cancer. We found 27 valid studies. The results of the meta-analysis showed a significant 22% reduction in breast cancer mortality with invitation to screening, with a relative risk of 0.78 (95% CI 0.75-0.82), and a significant 33% reduction with actual attendance at screening (RR 0.67, 95% CI 0.61-0.75). Breast cancer screening in the routine healthcare setting continues to confer a substantial reduction in mortality from breast cancer.

Screening mammography with special reference to guidelines in South Africa

Screening mammography is known to reduce mortality from breast cancer. Controversy regarding screening has led to much confusion in the medical fraternity. The purpose of this review is to point out the 'pros and cons' of screening. The benefits and perceived harms of screening will be discussed using evidence-based literature from the past 30 years. The literature was obtained from various journals sourced from the Internet. General findings are that screening mammography from the age of 40 saves lives, but that the problem of overdiagnosis and overtreatment of certain breast cancers overrides the benefit of screening. The article also covers the debate on what age to begin screening. Screening in the South African context is discussed. Screening in the future will need to be more selective of patients and of which cancers to treat less aggressively, if at all.

Absence of sustained breast cancer incidence inflation in a national mammography screening programme

OBJECTIVE

To investigate the impact of population mammography screening on breast cancer incidence trends in New Zealand.

METHODS

Trends in age-specific rates of invasive breast cancer incidence (1994-2014) were assessed in relation to screening in women aged 50-64 from 1999 and 45-69 following the programme age extension in mid-2004.

RESULTS

Breast cancer incidence increased significantly by 18% in women aged 50-64 compared with 1994-98 (p<0.0001), coinciding with the 1999 introduction of mammography screening, and remained elevated for four years, before declining to pre-screening levels. Increases over 1994-99 incidence occurred in the 45-49 (21%) and 65-69 (19%) age groups following the 2004 age extension (p<0.0001). Following establishment of screening (2006-10), elevated incidence in the screening target age groups was compensated for by lower incidence in the post-screening ⩾70 age groups than in 1994-98. Incidence in women aged ⩾45 was not significantly higher (+5%) after 2006 than in 1994-98. The cumulated risk of breast cancer in women aged 45-84 for 1994-98 was 10.7% compared with 10.8% in 2006-10.

CONCLUSIONS

Increases in breast cancer incidence following introduction of mammography screening in women aged 50-64 did not persist. Incidence inflation also occurred after introduction of screening for age groups 45-49 and 65-69. The cumulated incidence for women aged 45-84 over 2006-10 after screening was well established, compared with 1994-98 prior to screening, shows no increase in diagnosis. Over-diagnosis is not inevitable in population mammography screening programmes.

Breast cancer mortality and screening mammography in New Zealand: Incidence-based and aggregate analyses

OBJECTIVE

To investigate trends in breast cancer mortality in New Zealand women, to corroborate or negate a causal association with service screening mammography.

METHOD

Cumulated mortality rates from breast cancer deaths individually linked to incident cases diagnosed before and after screening commencement were compared, in women aged 50-64 (from 2001) and aged 45-49 and 65-69 (from 2006). Trends and differences in aggregate invasive breast cancer mortality (1975-2013) were assessed in relation to introduction of mammography screening targeting women aged 50-64 and 45-69. Joinpoint analysis was also undertaken.

RESULTS

The reduction in incidence-based cumulated breast cancer mortality before and after the introduction of screening was -15% (p = 0.006) for women aged 45-69, and 17% (p = 0.005) for those aged 50-64. Aggregate mortality declined by -34% (2005-13 compared with 1992-98) in the age group 50-64, and by -28% among women aged 45-49 and -25% among women aged 65-74. For women aged 50-64 the 2-joinpoint model shows a 1990 turning point, from prior rising mortality to a mean -1.8% decline per annum, coinciding with improvements in primary treatment of breast cancer; and a steepening of the decline (-3.0% p.a.) from the late 1990s, coinciding with the introduction of service mammography screening.

CONCLUSION

Breast cancer mortality declines occurring since the advent of screening mammography in New Zealand are consistent with other incidence-based and aggregate studies of screening mammography in populations, individual-based cohort studies, and randomized controlled trials.

A national cross-sectional study of adherence to timely mammography use in Malta

BACKGROUND

Routine mammography improves survival. To achieve health benefits, women must attend breast screening regularly at recommended time intervals. Maltese women are routinely invited to undergo mammography at three-year intervals at an organized breast screening programme (MBSP) or can opt to attend a private clinic. Previous research shows that health beliefs, particularly perceived barriers, were the most significant predictors of uptake to the first MBSP invitation. Whether these beliefs and other factors are predictive of adherence with recommended time intervals for mammography at organized or private screening in Malta is unknown. For the first time, this paper explores the predictors for Maltese women screened within or exceeding the recommended three-year frequency in organized or private screening in Malta.

METHODS

Information was obtained from a cross-sectional survey of 404 women, aged 50 to 60 years at the time of their first MBSP invitation, where women's characteristics, knowledge, health beliefs and illness perceptions were compared. The main variable of interest was women's mammography attendance within a three-year interval (ADHERENT) or exceeding three years (NON-ADHERENT). Data were analysed using descriptive statistics, chi-square test, Mann Whitney test, Independent Samples t-test and Shapiro Wilk test.

RESULTS

At the time of the survey, 80.2% (n = 324) had been screened within three years (ADHERENT), 5.9% (n = 24) had exceeded the three-year frequency (NON-ADHERENT) while 13.9% (n = 56) never had a mammogram. No significant associations were found between ADHERENT or NON-ADHERENT women in relation to sociodemographic or health status variables (p > 0.05). Knowledge of screening frequency was significantly associated with women's mammography adherence (χ2 = 5.5, p = 0.020). Health beliefs were the strongest significant predictors to describe the variance between ADHERENT and NON-ADHERENT screeners. When Mann Whitney test and Independent Samples t-test were applied on mammography adherence, perceived barriers and cues to action were found to be the most important predictors (p = 0.000, p = 0.039 respectively).

CONCLUSIONS

To increase routine and timely mammography practices, women who are non-adherent to recommended time frequency guidelines should be targeted, together with their health beliefs, predominantly perceived barriers and cues to action.

High Participation Rate in Mammography Screening: Experience from Croatia

OBJECTIVE

The aim of the study was to analyse the results of three cycles of mammography screening (MS) in the Croatian National Programme (CNP) for Early Breast Cancer Detection for women aged 50–69 years in the Bjelovar-Bilogora County (BBC) from 2006–2014.

METHODS

Data on women aged 50–69 screened during a 9-year period were obtained from the Croatian Cancer Registry and Institute of Public Health reports. Participation rate and performance indicators were examined.

RESULTS

The total of 57,428 women were invited to mammography screening in BBC during a 9-year period and 31,402 mammograms in total were performed. The response rate of 84% in BBC was consistently higher than the national average of about 60% reported in 2007, 2013 and 2014.

CONCLUSION

The National Programme in BBC has been carried out continuously for nine years with a higher response rate compared with the national average, as a result of additional efforts of the Croatian Institute of Public Health team, as well as good cooperation among all programme stakeholders. It was concluded that to achieve better results in the response of women to screening and consequently reduced mortality from breast cancer is possible through tailored health promotion activities.

Mammography service screening and breast cancer mortality in New Zealand: a National Cohort Study 1999-2011

Background:

This breast cancer mortality evaluation of service screening mammography in New Zealand, the first since commencement of screening in 1999, applies to the 1999–2011 diagnostic period. Individual-level linked information on mammography screening, breast cancer diagnosis and breast cancer mortality is used to analyse differences in breast cancer mortality according to participation in organised screening mammography, as provided by BreastScreen Aotearoa (BSA).

Methods:

Women were followed from the time they became eligible for screening, from age 50 years (1999–2004) and 45 years (⩾2004). Breast cancer mortality from cancers diagnosed during the screening period from 1999 to 2011 (n=4384) is examined in relation to individual screening participation or non-participation during preceding person-years of follow-up from the time of screening eligibility. To account for changes from never- to ever-screened status, breast cancer mortality is calculated for each year in relation to prior accumulated time of participation and non-participation in screening. Breast cancer mortality is also examined in regularly screened women (screened ⩾3 times and mean screening interval ⩽30 months), and irregularly screened women compared with never-screened women. Statistical analyses are by negative binomial and Poisson regression with adjustment for age and ethnic group (Māori, Pacific women) in a repeated-measures analysis. Relative risks for breast cancer mortality compared with never-screened women, are adjusted also for screening selection bias, to indicate the extent of breast cancer mortality reduction in a population offered and not offered mammography screening. Prognostic indicators at diagnosis of breast cancer are also compared between different screening participation groups, including by grade of tumour, extent of disease (spread), multiple tumour status and maximum tumour size using χ² statistics, t-tests and two-sample median tests.

Results:

For 1999–2011, after adjusting for age and ethnicity, breast cancer mortality in ever-screened women is estimated to be 62% (95% CI: 51–70) lower than in never-screened women. After further adjustment for screening selection bias, the mortality reduction in NZ is estimated to be 29% (95% CI: 20–38) at an average screening coverage of 64% for 2001–2011, and 34% (95% CI: 25–43) for recent screening coverage (2012–13, 71%). For irregularly screened women, the mortality reduction is estimated to be 31% (95% CI: 21–40), and 39% (95% CI: 22–52) in regularly screened women compared with never-screened women, after adjusting for age, ethnicity and screening selection bias (using recent 2012–2013 screening coverage of 71%). Ever-screened women diagnosed with breast cancer have more favourable prognostic indicators than never-screened women, with a higher proportion of localised cancer (63 compared with 46%), a higher proportion with a well-differentiated tumour (30 compared with 18%), lower risk of multiple tumours (RR=0.48) and smaller median tumour size (15 mm compared with 20 mm)—all differences are statistically significant (P<0.0001).

Conclusions:

This is the first total population cohort study of an established nation-wide screening mammography programme using individual-level information on screening participation and mortality outcomes from breast cancer. The findings are in accord with other mammography screening service evaluations and with randomised trials of mammography screening.

US-localized diffuse optical tomography in breast cancer: comparison with pharmacokinetic parameters of DCE-MRI and with pathologic biomarkers

BACKGROUND

To correlate parameters of Ultrasonography-guided Diffuse optical tomography (US-DOT) with pharmacokinetic features of Dynamic contrast-enhanced (DCE)-MRI and pathologic markers of breast cancer.

METHODS

Our institutional review board approved this retrospective study and waived the requirement for informed consent. Thirty seven breast cancer patients received US-DOT and DCE-MRI with less than two weeks in between imaging sessions. The maximal total hemoglobin concentration (THC) measured by US-DOT was correlated with DCE-MRI pharmacokinetic parameters, which included K(trans), k ep and signal enhancement ratio (SER). These imaging parameters were also correlated with the pathologic biomarkers of breast cancer.

RESULTS

The parameters THC and SER showed marginal positive correlation (r = 0.303, p = 0.058). Tumors with high histological grade, negative ER, and higher Ki-67 expression ≥ 20% showed statistically higher THC values compared to their counterparts (p = 0.019, 0.041, and 0.023 respectively). Triple-negative (TN) breast cancers showed statistically higher K(trans) values than non-TN cancers (p = 0.048).

CONCLUSION

THC obtained from US-DOT and K(trans) obtained from DCE-MRI were associated with biomarkers indicative of a higher aggressiveness in breast cancer. Although US-DOT and DCE-MRI both measured the vascular properties of breast cancer, parameters from the two imaging modalities showed a weak association presumably due to their different contrast mechanisms and depth sensitivities.

Imaging surveillance of patients with breast cancer after primary treatment: current recommendations

Women who have been treated for breast cancer are at risk for second breast cancers, such as ipsilateral recurrence or contralateral metachronous breast cancer. As the number of breast cancer survivors increases, interest in patient management and surveillance after treatment has also increased. However, post-treatment surveillance programs for patients with breast cancer have not been firmly established. In this review, we focus on the imaging modalities that have been used in post-treatment surveillance for patients with breast cancer, such as mammography, ultrasonography, magnetic resonance imaging, and positron emission tomography, the effectiveness of each modality for detecting recurrence, and how they can be applied to manage patients.

Differentiation of BIRADS-4 small breast lesions via Multimodal Ultrasound Tomography

PURPOSE

To demonstrate the use of a new 3D diagnostic imaging technology, termed Multimodal Ultrasonic Tomography (MUT), for the detection of solid breast lesions < 15 mm in maximum dimension.

METHODS AND MATERIALS

3D MUT imaging was performed on 71 volunteers presenting BIRADS-4 nodules, asymmetrical densities, and architectural distortions in X-ray mammograms, who subsequently underwent biopsy. MUT involved D tomographic imaging of the pendulant breast in a water bath using transmission ultrasound and constructed multimodal images corresponding to refractivity and frequency-dependent attenuation (calibrated relative to water). The multimodal images were fused into composite images and a composite index (CI) was calculated and used for diagnostic purposes. The composite images were evaluated against results of histopathology on biopsy specimens.

RESULTS

Histopathology revealed 22 malignant and 49 benign lesions. The pixels of 22 malignant lesions exhibited high values in both refractivity and attenuation, resulting in CI values > 1. In contrast, 99.9% of benign lesions and normal tissue pixels exhibited lower values of at least one of the attributes measured, corresponding to CI values < 1.

CONCLUSIONS

MUT imaging appears to differentiate small malignant solid breast lesions as exhibiting CI values >1, while benign lesions or normal breast tissues exhibit CI values <1.

KEY POINTS

• MUT was able to detect all 22 biopsy-confirmed malignant lesions. • MUT was able to differentiate the malignant from the benign lesions. • Additional MUT detections outside the biopsy area must be evaluated prospectively.

Influence of service characteristics on high priority performance indicators and standards in the BreastScreen Australia program

BACKGROUND

Data from BreastScreen Australia Screening and Assessment Services (SAS) for 2002-2010 were analysed to determine whether some SAS characteristics were more conducive that others to high screening performance, as indicated by high priority performance indicators and standards.

MATERIALS AND METHODS

Indicators investigated related to: numbers of benign open biopsies, screen-detected invasive cancers, and interval cancers, and wait times between screening and assessment. Multivariate Poisson regression was undertaken using as candidate predictors of performance, SAS size (screening volume), urban or rural location, year of screening, accreditation status, and percentages of clients from culturally and linguistically diverse backgrounds, rural and remote areas, and socio-economically disadvantaged areas.

RESULTS

Performance standards for benign biopsies and invasive cancer detection were uniformly met irrespective of SAS location and size. The interval cancer standard was also met, except in 2003 when the 95% confidence interval of the rate still incorporated the national standard. Performance indicators improved over time for: benign open biopsy for second or subsequent screening rounds; rates of invasive breast cancer detection for second or subsequent screening rounds; and rates of small cancer detection. No differences were found over time in interval cancer rates. Interval cancer rates did not differ between non-metropolitan and metropolitan SAS, although state-wide SAS had lower rates. The standard for wait time between screening and assessment (being assessed <28 days) was mostly unmet and this applied in particular to SAS with high percentages of culturally and linguistically diverse women in their screening populations.

CONCLUSIONS

Gains in performance were observed, and all performance standards were met irrespective of SAS characteristics, except wait times to assessment. Additional descriptive data should be collected on SAS characteristics, and their associations with favourable screening performance, as these may be important when deciding on SAS design.

Screening mammography & breast cancer mortality: meta-analysis of quasi-experimental studies

Background

The magnitude of the benefit associated with screening has been debated. We present a meta-analysis of quasi-experimental studies on the effects of mammography screening.

Methods

We searched MEDLINE/PubMed and Embase for articles published through January 31, 2013. Studies were included if they reported: 1) a population-wide breast cancer screening program using mammography with 5+ years of data post-implementation; 2) a comparison group with equal access to therapies; and 3) breast cancer mortality. Studies excluded were: RCTs, case-control, or simulation studies. We defined quasi-experimental as studies that compared either geographical, historical or birth cohorts with a screening program to an equivalent cohort without a screening program. Meta-analyses were conducted in Stata using the metan command, random effects. Meta-analyses were conducted separately for ages screened: under 50, 50 to 69 and over 70 and weighted by population and person-years.

Results

Among 4,903 published papers that were retrieved, 19 studies matched eligibility criteria. Birth cohort studies reported a significant benefit for women screened <age 50, but not for women screened ages 50–69. Significant reductions in breast cancer mortality were observed in historical comparisons. For geographical comparisons, there was a significant 20% reduction in mortality for women <age 50 and a significant 21–22% reduction for women ages 50–69. Studies that tested the interaction of geographical and historical comparisons produced a pooled, significant 13–17% reduction in incident breast cancer mortality for women ages 50–69, but the effects in most individual studies were non-significant. All studies of women ages 70+ were non-significant.

Conclusions

Mammography screening may have modest effects on cancer mortality between the ages of 50 and 69 and non-significant effects for women older than age 70. Results are consistent with meta-analyses of RCTs. Effects on total mortality could not be assessed because of the limited number of studies.

Health and economic impact of breast cancer mortality in young women, 1970-2008

BACKGROUND

Breast cancer is the second-leading cause of cancer-related deaths among women aged <50 years. Studies on the effects of breast cancer mortality among young women are limited.

PURPOSE

To assess trends in breast cancer mortality rates among women aged 20-49 years, estimate years of potential life lost (YPLL), and the value of productivity losses due to premature mortality.

METHODS

Age-adjusted rates and rate ratios (RRs) were calculated using 1970-2008 U.S. mortality data. Breast cancer mortality rates over time were assessed using Joinpoint regression modeling. YPLL was calculated using number of cancer deaths and the remaining life expectancy at the age of death. Value of productivity losses was estimated using the number of deaths and the present value of future lifetime earnings.

RESULTS

From 1970 to 2008, the age-adjusted breast cancer mortality rate among young women was 12.02/100,000. Rates were higher in the Northeast (RR=1.03, 95% CI, 1.02-1.04). The annual decline in breast cancer mortality rates among blacks was smaller (-0.68%) compared with whites (-2.02%). The total number of deaths associated with breast cancer was 225,866, which accounted for an estimated 7.98 million YPLL. The estimated total productivity loss in 2008 was $5.49 billion and individual lifetime lost earnings were $1.10 million.

CONCLUSIONS

Considering the effect of breast cancer on women of working age and the disproportionate impact on black women, more age-appropriate interventions with multiple strategies are needed to help reduce these substantial health and economic burdens, improve survival, and in turn reduce productivity costs associated with premature death.

Real and artificial controversies in breast cancer screening

SUMMARY We review the apparent disparities between different reviews of the effects of mammographic screening on mortality from breast cancer and overdiagnosis. When results of each review are expressed with respect to a common population and a common baseline, all find a substantial mortality benefit and variation among estimates is minor. There are genuine disagreements about overdiagnosis, but methods that take account of lead time and underlying incidence trends yield estimates of overdiagnosis that are modest and are outweighed by the mortality benefit. There is potential for individualized screening regimens, particularly with respect to breast density.

The impact of mammographic screening on breast cancer mortality in Europe: a review of observational studies

OBJECTIVES

To assess the impact of population-based mammographic screening on breast cancer mortality in Europe, considering different methodologies and limitations of the data.

METHODS

We conducted a systematic literature review of European trend studies (n = 17), incidence-based mortality (IBM) studies (n = 20) and case-control (CC) studies (n = 8). Estimates of the reduction in breast cancer mortality for women invited versus not invited and/or for women screened versus not screened were obtained. The results of IBM studies and CC studies were each pooled using a random effects meta-analysis.

RESULTS

Twelve of the 17 trend studies quantified the impact of population-based screening on breast cancer mortality. The estimated breast cancer mortality reductions ranged from 1% to 9% per year in studies reporting an annual percentage change, and from 28% to 36% in those comparing post- and prescreening periods. In the IBM studies, the pooled mortality reduction was 25% (relative risk [RR] 0.75, 95% confidence interval [CI] 0.69-0.81) among invited women and 38% (RR 0.62, 95% CI 0.56-0.69) among those actually screened. The corresponding pooled estimates from the CC studies were 31% (odds ratio [OR] 0.69, 95% CI 0.57-0.83), and 48% (OR 0.52, 95% CI 0.42-0.65) adjusted for self-selection.

CONCLUSIONS

Valid observational designs are those where sufficient longitudinal individual data are available, directly linking a woman's screening history to her cause of death. From such studies, the best 'European' estimate of breast cancer mortality reduction is 25-31% for women invited for screening, and 38-48% for women actually screened. Much of the current controversy on breast cancer screening is due to the use of inappropriate methodological approaches that are unable to capture the true effect of mammographic screening.

Mammographic screening and breast cancer mortality: a case-control study and meta-analysis

BACKGROUND

Observational studies are necessary to assess the impact of population screening on breast cancer mortality. While some ecological studies have notably found little or no association, case-control studies consistently show strong inverse associations, but they are sometimes ignored, perhaps due to theoretical biases arising from the study design. We conducted a case-control study of breast cancer deaths in Western Australia to evaluate the effect of participation in the BreastScreen Australia program, paying particular attention to potential sources of bias, and undertook an updated meta-analysis of case-control studies.

METHODS

Our study included 427 cases (women who died from breast cancer), each matched to up to 10 controls. We estimated the association between screening participation and breast cancer mortality, quantifying the effect of potential sources of bias on our findings, including selection bias, information bias, and confounding. We also conducted a meta-analysis of published case-control studies.

RESULTS

The OR for participation in the Western Australian BreastScreen program in relation to death from breast cancer was 0.48 [95% confidence interval (CI), 0.38-0.59; P < 0.001]. We were unable to identify biases that could negate this finding: sensitivity analyses generated ORs from 0.45 to 0.52. Our meta-analysis yielded an OR of 0.51 (95% CI, 0.46-0.55).

CONCLUSIONS

Our findings suggest an average 49% reduction in breast cancer mortality for women who are screened. In practice, theoretical biases have little effect on estimates from case-control studies.

IMPACT

Case-control studies, such as ours, provide robust and consistent evidence that screening benefits women who choose to be screened.

Mammography screening and breast cancer mortality in Australia: an aggregate cohort study

BACKGROUND

Evidence that mammography screening reduces breast cancer mortality derives from trials, with observational studies broadly supporting trial findings. The purpose of this study was to evaluate the national mammographic screening programme, BreastScreen Australia, using aggregate screening and breast cancer mortality data.

METHODS

Breast cancer mortality from 1990 to 2004 in the whole Australian population was assessed in relation to screening exposure in the target of women aged 50-69 years. Population cohorts were defined by year of screening (and diagnosis), five-year age group at screening (and diagnosis), and local area of residence at screening (and diagnosis). Biennial screening data for BreastScreen Australia were related to cumulated mortality from breast cancer in an event analysis using Poisson regression, and in a time-to-event analysis using Cox proportional hazards regression. Results were adjusted for repeated measures and the potential effects of mammography outside BreastScreen Australia, regionality, and area socio-economic status.

RESULTS

From the adjusted Poisson regression model, a 22% (95% CI:12-31%) reduction in six-year cumulated mortality from breast cancer was predicted for screening participation of approximately 60%, compared with no screening; 21% (95% CI:11-30%) for the most recently reported screening participation of 56%; and 25% (95% CI:15-35%) for the programme target of 70% biennial screening participation. Corresponding estimates from the Cox proportional hazard regression model were 30% (95% CI:17-41%), 28% (95% CI:16-38%) and 34% (95% CI:20-46%).

CONCLUSIONS

Despite data limitations, the results of this nationwide study are consistent with the trial evidence, and with results of other service studies of mammography screening. With sufficient participation, mammography screening substantially reduces mortality from breast cancer.

Mammography Screening: Keeping Women Alive

Evaluation of: Tabár L, Vitak B, Chen TH et al. Swedish Two-County Trial: impact of mammographic screening on breast cancer mortality during 3 decades. Radiology 260(3), 658–663 (2011). In the 1980s, the periodic invitation of women aged 40–69 years for mammographic screening in the Swedish Two-County Trial showed a strong 30% reduction in breast cancer mortality. The result of 2–3-yearly mammographic examinations has persisted throughout the long follow-up of three decades. Through the richness of the collected and verified data, the trial has also demonstrated a substantial and absolute reduction in mortality risk. For each 414 women screened for 7 years (approximately four screening examinations), one breast cancer death was prevented. Transferring these outcomes to, for example, the national program of the UK, for every 1000 women aged 47–73 years attending the 3-yearly screenings (nine screening examinations) at least five to seven breast cancer deaths would be prevented. In recent follow-up papers by the Swedish trial group, the major human cost of screening (false-positive outcome, occurrence of interval cancer, overdiagnosis and radiation exposure) were judged to be in balance with the accurately demonstrated mortality benefit.

The evidence base for breast cancer screening

The history of breast cancer screening is littered with controversy. With 10 trials spanning 4 decades, we have a substantial body of evidence, but with different aims and flaws. Combined analysis of the intention-to-treat results gives an overall relative reduction in breast cancer mortality of 19% (95% CI 12%-26%), which, if adjusted for non-attendance gives an approximate 25% relative reduction for those who attend screening. However, given that 4% of all-cause mortality is due to breast cancer deaths, this translates into a less than 1% reduction in all-cause mortality. An emerging issue in interpretation is the improvements in treatment since these trials recruited women. Modern systemic therapy would have improved survival (models suggest between 12% and 21%) in both screened and non-screened groups, which would result in a lesser difference in absolute risk reduction from screening but probably a similar, or slightly smaller, relative risk reduction. However benefits and harms, particularly over-diagnosis, need to balanced and differ by age-groups. The informed views of recipients of screening are needed to guide current and future policy on screening.

Increasingly strong reduction in breast cancer mortality due to screening

BACKGROUND

Favourable outcomes of breast cancer screening trials in the 1970s and 1980s resulted in the launch of population-based service screening programmes in many Western countries. We investigated whether improvements in mammography and treatment modalities have had an influence on the effectiveness of breast cancer screening from 1975 to 2008.

METHODS

In Nijmegen, the Netherlands, 55,529 women received an invitation for screening between 1975 and 2008. We designed a case-referent study to evaluate the impact of mammographic screening on breast cancer mortality over time from 1975 to 2008. A total number of 282 breast cancer deaths were identified, and 1410 referents aged 50-69 were sampled from the population invited for screening. We estimated the effectiveness by calculating the odds ratio (OR) indicating the breast cancer death rate for screened vs unscreened women.

RESULTS

The breast cancer death rate in the screened group over the complete period was 35% lower than in the unscreened group (OR=0.65; 95% CI=0.49-0.87). Analysis by calendar year showed an increasing effectiveness from a 28% reduction in breast cancer mortality in the period 1975-1991 (OR=0.72; 95% CI=0.47-1.09) to 65% in the period 1992-2008 (OR=0.35; 95% CI=0.19-0.64).

CONCLUSION

Our results show an increasingly strong reduction in breast cancer mortality over time because of mammographic screening.

Balancing sensitivity and specificity: sixteen year's of experience from the mammography screening programme in Copenhagen, Denmark

AIM

To report on sensitivity and specificity from 7 invitation rounds of the organised, population-based mammography screening programme started in Copenhagen, Denmark, in 1991, and offered biennially to women aged 50-69. Changes over time were related to organisation and technology.

METHODS

Individualized data were retrieved on outcome of screening mammography, assessment, surgery, and interval cancers. European Guideline performance indicators were calculated, supplemented with false positive and interval cancer rates per 1000 screens. False positive tests were divided into those sorted out at assessment (Type 1) and at surgery (Type 2).

RESULTS

In total, 1392 invasive breast cancers/ductal carcinoma in situ cases (DCIS) were diagnosed, giving an overall detection rate of 7.6 per 1000 screens. Of 5178 false positive tests, 4666 were Type 1 and 512 Type 2. The 468 interval cancers constituted 25% of all breast cancers (=screen detected+interval cancer). Almost all outcome measures were well within the desirable level of the European Guidelines. Risk of Type 2 false positive tests was positively associated with detection rate especially at initial screen, and interval cancer rate was negatively associated with detection rate. This association was decoupled after introduction of high resolution ultrasound and stereotactic breast biopsies, resulting in a Benign-to-Malignant-Ratio (BMR) of 1:11.40.

CONCLUSION

Mammography screening is a delicate balance between benefits and risks. Increase in detection rate came at cost of increase in risk of benign biopsies. Introduction of new technologies broke this pattern and a slight increase in detection rate coincided with an unprecedentedly low BMR.

Breast cancer mortality in organised mammography screening in Denmark: comparative study

OBJECTIVE

To determine whether the previously observed 25% reduction in breast cancer mortality in Copenhagen following the introduction of mammography screening was indeed due to screening, by using an additional screening region and five years additional follow-up.

DESIGN

We used Poisson regression analyses adjusted for changes in age distribution to compare the annual percentage change in breast cancer mortality in areas where screening was used with the change in areas where it was not used during 10 years before screening was introduced and for 10 years after screening was in practice (starting five years after introduction of screening).

SETTING

Copenhagen, where mammography screening started in 1991, and Funen county, where screening was introduced in 1993. The rest of Denmark (about 80% of the population) served as an unscreened control group.

PARTICIPANTS

All Danish women recorded in the Cause of Death Register and Statistics Denmark for 1971-2006.

MAIN OUTCOME MEASURE

Annual percentage change in breast cancer mortality in regions offering mammography screening and those not offering screening.

RESULTS

In women who could benefit from screening (ages 55-74 years), we found a mortality decline of 1% per year in the screening areas (relative risk (RR) 0.99, 95% confidence interval (CI) 0.96 to 1.01) during the 10 year period when screening could have had an effect (1997-2006). In women of the same age in the non-screening areas, there was a decline of 2% in mortality per year (RR 0.98, 95% CI 0.97 to 0.99) in the same 10 year period. In women who were too young to benefit from screening (ages 35-55 years), breast cancer mortality during 1997-2006 declined 5% per year (RR 0.95, CI 0.92 to 0.98) in the screened areas and 6% per year (RR 0.94, CI 0.92 to 0.95) in the non-screened areas. For the older age groups (75-84 years), there was little change in breast cancer mortality over time in both screened and non-screened areas. Trends were less clear during the 10 year period before screening was introduced, with a possible increase in mortality in women aged less than 75 years in the non-screened regions.

CONCLUSIONS

We were unable to find an effect of the Danish screening programme on breast cancer mortality. The reductions in breast cancer mortality we observed in screening regions were similar or less than those in non-screened areas and in age groups too young to benefit from screening, and are more likely explained by changes in risk factors and improved treatment than by screening mammography.

Breast cancer screening: emerging role of new imaging techniques as adjuncts to mammography

Early detection of breast cancer has been shown to reduce breast cancer deaths in randomised controlled trials (RCTs) of mammography in women aged 50-69 years, with weaker evidence of benefit in those aged 40-49 or 70 years and older. Magnetic resonance imaging (MRI) and ultrasonography have been evaluated in breast cancer screening, relative to, or in addition to, mammography, in selected populations; neither test has been examined in an RCT, and thus evidence of associated screening benefit is uncertain. MRI is more sensitive than mammography in screening women with suspected or proven inherited mutations of the breast cancer genes. The addition of MRI in screening this population detects 8-24 additional cancers per 1000 screens, but also significantly increases a woman's risk of being recalled for investigation or surgical biopsy for false-positive findings. In Australia, Medicare funding for MRI screening of women in specific risk groups was announced in February 2009. Ultrasonography can detect cancers not identified on mammography in asymptomatic women with dense breast tissue. Incremental ultrasound cancer detection is reported in 0.27%-0.46% of women with mammography-negative dense breasts; evidence varies on its association with false-positive findings. Computer-aided detection (CAD) is a complementary tool to mammography, prompting the reader to consider lesions on the mammogram that may represent cancer. Emerging evidence and improved CAD technology are likely to help define its role in breast screening.

Computer-assisted diagnosis (CAD) in mammography: comparison of diagnostic accuracy of a new algorithm (Cyclopus, Medicad) with two commercial systems

PURPOSE

The study compares the diagnostic accuracy (correct identification of cancer) of a new computer-assisted diagnosis (CAD) system (Cyclopus) with two other commercial systems (R2 and CADx).

MATERIALS AND METHODS

Cyclopus was tested on a set of 120 mammograms on which the two compared commercial systems had been previously tested. The set consisted of mammograms reported as negative, preceding 31 interval cancers reviewed as screening error or minimal sign, and of 89 verified negative controls randomly selected from the same screening database.

RESULTS

Cyclopus sensitivity was 74.1% (R2=54.8%; CADx=41.9%) and was higher for interval cancers reviewed as screening error (90.9%; R2=54.5%; CADx=81.8%) compared with those reviewed as minimal sign (65.0%; R2=55.0%; CADx=20.0%). Specificity was 15.7% (R2=29.2%; CADx=17.9%). Overall accuracy was 30.8% (R2=35.8%; CADx=24.1%). The positive predictive value of a case with CAD marks [regions of interest (ROI)] was 23.4% (23/98; R2=16.0%; CADx=15.1%). Average ROI number per view among negative controls was 1.13 (R2=0.93; CADx=0.99). Cyclopus was more sensitive for masses compared with isolated microcalcifications (208 vs 62 ROI; R2=90 vs 213; CADx=192 vs 130).

CONCLUSIONS

Compared with two other commercial systems, Cyclopus was more sensitive (R2 p=0.14; CADx p=0.02) and less specific (R2 p=0.02; CADx p=0.64).

Effectiveness of organised versus opportunistic mammography screening

BACKGROUND

Detailed comparison of effectiveness between organised and opportunistic mammography screening operating in the same country has seldom been carried out.

PATIENTS AND METHODS

Prognostic indicators, as defined in the European Guidelines, were used to evaluate screening effectiveness in Switzerland. Matching of screening programmes' records with population-based cancer registries enabled to compare indicators of effectiveness by screening and detection modality (organised versus opportunistic screening, unscreened, interval cancers). Comparisons of prognostic profile were also drawn with two Swiss regions uncovered by service screening of low and high prevalence of opportunistic screening, respectively.

RESULTS

Opportunistic and organised screening yielded overall little difference in prognostic profile. Both screening types led to substantial stage shifting. Breast cancer prognostic indicators were systematically more favourable in Swiss regions covered by a programme. In regions without a screening programme, the higher the prevalence of opportunistic screening, the better was the prognostic profile.

CONCLUSIONS

Organised screening appeared as effective as opportunistic screening. Mammography screening has strongly influenced the stage distribution of breast cancer in Switzerland, and a favourable impact on mortality is anticipated. Extension of organised mammography screening to the whole of Switzerland can be expected to further improve breast cancer prognosis in a cost-effective way.

Impact of a mammography screening programme on the breast cancer population of the Region of Valencia (Spain)

OBJECTIVE

Randomised clinical trials with a control arm of non-screened patients are nowadays ethically impossible. The aim of this study was to establish the impact of mammography screening on a non-selected population.

PATIENTS AND METHODS

Between January 1993 and December 2002, 3662 patients were included, 2313 in the screened group and 1349 in the unscreened group.

RESULTS

55.3% of the screened patients were diagnosed in stage I vs. 26.1% in the non-screened group. The proportion of stage III-IV was 4.6% and 19.8% for the screened and unscreened groups respectively (p<0.001). 48.8% in the screening group were submitted to mastectomy vs. 66.4% of the unscreened patients (p<0.001). Overall survival was superior for the prevalent cases in the screening group, with a relative risk of 0.49, and was not significant for the incident cases.

CONCLUSIONS

Diagnosis of breast cancer in the mammography screening programme of the Region of Valencia significantly increases conservative surgery rates and suggests an improvement in survival in prevalent cases. The increased rate of early stages in these patients could be the main reason of this benefit.