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Autier P, Boniol M. Mammography screening: A major issue in medicine. Eur J Cancer 2017; 90:34-62. [PMID: 29272783 DOI: 10.1016/j.ejca.2017.11.002] [Citation(s) in RCA: 81] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2017] [Accepted: 11/03/2017] [Indexed: 01/20/2023]
Abstract
Breast cancer mortality is declining in most high-income countries. The role of mammography screening in these declines is much debated. Screening impacts cancer mortality through decreasing the incidence of number of advanced cancers with poor prognosis, while therapies and patient management impact cancer mortality through decreasing the fatality of cancers. The effectiveness of cancer screening is the ability of a screening method to curb the incidence of advanced cancers in populations. Methods for evaluating cancer screening effectiveness are based on the monitoring of age-adjusted incidence rates of advanced cancers that should decrease after the introduction of screening. Likewise, cancer-specific mortality rates should decline more rapidly in areas with screening than in areas without or with lower levels of screening but where patient management is similar. These two criteria have provided evidence that screening for colorectal and cervical cancer contributes to decreasing the mortality associated with these two cancers. In contrast, screening for neuroblastoma in children was discontinued in the early 2000s because these two criteria were not met. In addition, overdiagnosis - i.e. the detection of non-progressing occult neuroblastoma that would not have been life-threatening during the subject's lifetime - is a major undesirable consequence of screening. Accumulating epidemiological data show that in populations where mammography screening has been widespread for a long time, there has been no or only a modest decline in the incidence of advanced cancers, including that of de novo metastatic (stage IV) cancers at diagnosis. Moreover, breast cancer mortality reductions are similar in areas with early introduction and high penetration of screening and in areas with late introduction and low penetration of screening. Overdiagnosis is commonplace, representing 20% or more of all breast cancers among women invited to screening and 30-50% of screen-detected cancers. Overdiagnosis leads to overtreatment and inflicts considerable physical, psychological and economic harm on many women. Overdiagnosis has also exerted considerable disruptive effects on the interpretation of clinical outcomes expressed in percentages (instead of rates) or as overall survival (instead of mortality rates or stage-specific survival). Rates of radical mastectomies have not decreased following the introduction of screening and keep rising in some countries (e.g. the United States of America (USA)). Hence, the epidemiological picture of mammography screening closely resembles that of screening for neuroblastoma. Reappraisals of Swedish mammography trials demonstrate that the design and statistical analysis of these trials were different from those of all trials on screening for cancers other than breast cancer. We found compelling indications that these trials overestimated reductions in breast cancer mortality associated with screening, in part because of the statistical analyses themselves, in part because of improved therapies and underreporting of breast cancer as the underlying cause of death in screening groups. In this regard, Swedish trials should publish the stage-specific breast cancer mortality rates for the screening and control groups separately. Results of the Greater New York Health Insurance Plan trial are biased because of the underreporting of breast cancer cases and deaths that occurred in women who did not participate in screening. After 17 years of follow-up, the United Kingdom (UK) Age Trial showed no benefit from mammography screening starting at age 39-41. Until around 2005, most proponents of breast screening backed the monitoring of changes in advanced cancer incidence and comparative studies on breast cancer mortality for the evaluation of breast screening effectiveness. However, in an attempt to mitigate the contradictions between results of mammography trials and population data, breast-screening proponents have elected to change the criteria for the evaluation of cancer screening effectiveness, giving precedence to incidence-based mortality (IBM) and case-control studies. But practically all IBM studies on mammography screening have a strong ecological component in their design. The two IBM studies done in Norway that meet all methodological requirements do not document significant reductions in breast cancer mortality associated with mammography screening. Because of their propensity to exaggerate the health benefits of screening, case-control studies may demonstrate that mammography screening could reduce the risk of death from diseases other than breast cancer. Numerous statistical model approaches have been conducted for estimating the contributions of screening and of patient management to reductions in breast cancer mortality. Unverified assumptions are needed for running these models. For instance, many models assume that if screening had not occurred, the majority of screen-detected asymptomatic cancers would have progressed to symptomatic advanced cancers. This assumption is not grounded in evidence because a large proportion of screen-detected breast cancers represent overdiagnosis and hence non-progressing tumours. The accumulation of population data in well-screened populations diminishes the relevance of model approaches. The comparison of the performance of different screening modalities - e.g. mammography, digital mammography, ultrasonography, magnetic resonance imaging (MRI), three-dimensional tomosynthesis (TDT) - concentrates on detection rates, which is the ability of a technique to detect more cancers than other techniques. However, a greater detection rate tells little about the capacity to prevent interval and advanced cancers and could just reflect additional overdiagnosis. Studies based on the incidence of advanced cancers and on the evaluation of overdiagnosis should be conducted before marketing new breast-imaging technologies. Women at high risk of breast cancer (i.e. 30% lifetime risk and more), such as women with BRCA1/2 mutations, require a close breast surveillance. MRI is the preferred imaging method until more radical risk-reduction options are eventually adopted. For women with an intermediate risk of breast cancer (i.e. 10-29% lifetime risk), including women with extremely dense breast at mammography, there is no evidence that more frequent mammography screening or screening with other modalities actually reduces the risk of breast cancer death. A plethora of epidemiological data shows that, since 1985, progress in the management of breast cancer patients has led to marked reductions in stage-specific breast cancer mortality, even for patients with disseminated disease (i.e. stage IV cancer) at diagnosis. In contrast, the epidemiological data point to a marginal contribution of mammography screening in the decline in breast cancer mortality. Moreover, the more effective the treatments, the less favourable are the harm-benefit balance of screening mammography. New, effective methods for breast screening are needed, as well as research on risk-based screening strategies.
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Affiliation(s)
- Philippe Autier
- University of Strathclyde Institute of Global Public Health at IPRI, International Prevention Research Institute, Espace Européen, Building G, Allée Claude Debussy, 69130 Ecully Lyon, France; International Prevention Research Institute (iPRI), 95 Cours Lafayette, 69006 Lyon, France.
| | - Mathieu Boniol
- University of Strathclyde Institute of Global Public Health at IPRI, International Prevention Research Institute, Espace Européen, Building G, Allée Claude Debussy, 69130 Ecully Lyon, France; International Prevention Research Institute (iPRI), 95 Cours Lafayette, 69006 Lyon, France
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Keen JD, Jørgensen KJ. Four Principles to Consider Before Advising Women on Screening Mammography. J Womens Health (Larchmt) 2015; 24:867-74. [PMID: 26496048 PMCID: PMC4649764 DOI: 10.1089/jwh.2015.5220] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This article reviews four important screening principles applicable to screening mammography in order to facilitate informed choice. The first principle is that screening may help, hurt, or have no effect. In order to reduce mortality and mastectomy rates, screening must reduce the rate of advanced disease, which likely has not happened. Through overdiagnosis, screening produces substantial harm by increasing both lumpectomy and mastectomy rates, which offsets the often-promised benefit of less invasive therapy. Next, all-cause mortality is the most reliable way to measure the efficacy of a screening intervention. Disease-specific mortality is biased due to difficulties in attribution of cause of death and to increased mortality due to overdiagnosis and the resulting overtreatment with radiotherapy and chemotherapy. To enhance participation, the benefit from screening is often presented in relative instead of absolute terms. Third, some screening statistics must be interpreted with caution. Increased survival time and the percentage of early-stage tumors at detection sound plausible, but are affected by lead-time and length biases. In addition, analyses that only include women who attend screening cannot reliably correct for selection bias. The final principle is that accounting for tumor biology is important for accurate estimates of lead time, and the potential benefit from screening. Since “early detection” is actually late in a tumor's lifetime, the time window when screen detection might extend a woman's life is narrow, as many tumors that can form metastases will already have done so. Instead of encouraging screening mammography, physicians should help women make an informed decision as with any medical intervention.
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Affiliation(s)
- John D Keen
- 1 Department of Radiology, John H. Stroger Jr. Hospital of Cook County , Chicago, Illinois
| | - Karsten J Jørgensen
- 2 The Nordic Cochrane Centre, Rigshospitalet Department, Copenhagen , Denmark
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Robertson DJ, Kaminski MF, Bretthauer M. Effectiveness, training and quality assurance of colonoscopy screening for colorectal cancer. Gut 2015; 64:982-90. [PMID: 25804631 DOI: 10.1136/gutjnl-2014-308076] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 02/07/2015] [Indexed: 12/14/2022]
Abstract
Screening for colorectal cancer has been proven to be effective in reducing colorectal cancer incidence and mortality. While the precise benefit of screening exclusively by colonoscopy is not yet known, unarguably, the exam is central to the success of any screening programme. The test affords the opportunity to detect and resect neoplasia across the entire large bowel and is the definitive examination when other screening tests are positive. However, colonoscopy is invasive and often requires sedation as well as extensive bowel preparation, all of which puts the patient at risk. Furthermore, the test can technically be demanding and, unarguably, there is variation in how it is performed. This variation in performance has now been definitively linked to important outcome measures. For example, interval cancers are more common in low adenoma detectors as compared with high adenoma detectors. This review outlines the most current thinking regarding the effectiveness of colonoscopy as a screening tool. It also outlines key concepts to optimise its performance through robust quality assurance programmes and high-quality training.
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Affiliation(s)
- Douglas J Robertson
- VA Medical Center, White River Junction, Vermont, USA Geisel School of Medicine at Dartmouth, Hanover, New Hampshire, USA
| | - Michal F Kaminski
- Department of Gastroenterology and Hepatology, Medical Center for Postgraduate Education, Warsaw, Poland Maria Sklodowska-Curie Memorial Cancer Center and Institute of Oncology, Warsaw, Poland Institute of Health and Society, University of Oslo, Oslo, Norway
| | - Michael Bretthauer
- Institute of Health and Society, University of Oslo, Oslo, Norway Department of Transplantation Medicine, Oslo University Hospital, Oslo, Norway
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Bell RJ. Screening mammography--early detection or over-diagnosis? Contribution from Australian data. Climacteric 2014; 17 Suppl 2:66-72. [PMID: 25224048 DOI: 10.3109/13697137.2014.956718] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
OBJECTIVE The aim of this review was to examine the benefits and harms of organized screening mammography, with particular reference to data from Australia. METHODS Published literature was examined relating to the impact of screening mammography on breast cancer-specific mortality, the trends in use of adjuvant treatments for breast cancer, the effectiveness of adjuvant treatment in terms of breast cancer-specific mortality, the impact of breast cancer treatment on non-breast cancer mortality and the magnitude of the issue of over-diagnosis. RESULTS Most of the recent reduction in breast cancer-specific mortality is explained by use of adjuvant therapy rather than screening mammography. The impact of screening mammography in countries where women present with early disease and have access to adjuvant treatment is modest. There is a wide range of estimates for the magnitude of over-diagnosis. All-cause mortality (rather than breast cancer-specific mortality) should be used when assessing the impact of mammographic screening as otherwise the harm of breast cancer treatment in women who are over-diagnosed will be missed. CONCLUSIONS The benefits and harms of screening mammography are finely balanced. The impact of screening mammography is at best neutral but may result in overall harm. Women should be informed of the issue of over-diagnosis. It is time to review whether organized mammographic screening programs should continue.
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Affiliation(s)
- R J Bell
- Women's Health Research Program, Monash University School of Public Health and Preventive Medicine , Melbourne, Victoria , Australia
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Paap E, Verbeek ALM, Botterweck AAM, van Doorne-Nagtegaal HJ, Imhof-Tas M, de Koning HJ, Otto SJ, de Munck L, van der Steen A, Holland R, den Heeten GJ, Broeders MJM. Breast cancer screening halves the risk of breast cancer death: a case-referent study. Breast 2014; 23:439-44. [PMID: 24713277 DOI: 10.1016/j.breast.2014.03.002] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2013] [Revised: 03/03/2014] [Accepted: 03/03/2014] [Indexed: 10/25/2022] Open
Abstract
Large-scale epidemiologic studies have consistently demonstrated the effectiveness of mammographic screening programs, however the benefits are still subject to debate. We estimated the effect of the Dutch screening program on breast cancer mortality. In a large multi-region case-referent study, we identified all breast cancer deaths in 2004 and 2005 in women aged 50-75 who had been invited for screening (cases). Cases were individually matched to referents from the population invited to screening. Conditional logistic regression was used to estimate the odds ratio (OR) of breast cancer death according to individual screening history. The OR was adjusted for self-selection bias using regional correction factors for the difference in baseline risk for breast cancer death between screened and unscreened women. A total of 1233 cases and 2090 referents were included in this study. We found a 58% reduction in breast cancer mortality in screened versus unscreened women (adjusted OR = 0.42, 95% CI 0.33-0.53). Screening, i.e. early detection and treatment, has resulted in a substantial reduction in breast cancer mortality, indicating that the Dutch breast cancer screening program is highly effective.
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Affiliation(s)
- Ellen Paap
- Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands; National Expert and Training Centre for Breast Cancer Screening, Nijmegen, The Netherlands
| | - André L M Verbeek
- Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands
| | | | | | - Mechli Imhof-Tas
- Department of Radiology, Radboud University Medical Center, Nijmegen, The Netherlands; Screening Program Early Detection of Breast Cancer in the Eastern Part of the Netherlands, Nijmegen, The Netherlands
| | - Harry J de Koning
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Suzie J Otto
- Department of Public Health, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - Linda de Munck
- Comprehensive Cancer Centre the Netherlands, Utrecht, The Netherlands
| | - Annemieke van der Steen
- Screening Program Early Detection of Breast Cancer in the South-West Part of the Netherlands, Vlaardingen, The Netherlands
| | - Roland Holland
- National Expert and Training Centre for Breast Cancer Screening, Nijmegen, The Netherlands
| | - Gerard J den Heeten
- National Expert and Training Centre for Breast Cancer Screening, Nijmegen, The Netherlands; Department of Radiology, Academic Medical Centre, University of Amsterdam, The Netherlands
| | - Mireille J M Broeders
- Department for Health Evidence, Radboud University Medical Center, Nijmegen, The Netherlands; National Expert and Training Centre for Breast Cancer Screening, Nijmegen, The Netherlands.
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Marmot MG, Altman DG, Cameron DA, Dewar JA, Thompson SG, Wilcox M. The benefits and harms of breast cancer screening: an independent review. Br J Cancer 2013; 108:2205-40. [PMID: 23744281 PMCID: PMC3693450 DOI: 10.1038/bjc.2013.177] [Citation(s) in RCA: 622] [Impact Index Per Article: 56.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- M G Marmot
- UCL Department of Epidemiology and Public Health, UCL Institute of Health Equity, 1-19 Torrington Place, London WC1E 7HB,
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Vannier MW. Screening mammography: what good is it and how can we know if it works? J Natl Cancer Inst 2012; 104:1039-40. [PMID: 22811440 PMCID: PMC3731436 DOI: 10.1093/jnci/djs289] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/24/2012] [Indexed: 12/02/2022] Open
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Javitt MC, Hendrick RE, Keen JD, Jørgensen KJ, Orton CG. Recent data show that mammographic screening of asymptomatic women is effective and essential. Med Phys 2012; 39:4047-50. [DOI: 10.1118/1.3694115] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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