National expenditure for false-positive mammograms and breast cancer overdiagnoses estimated at $4 billion a year

Should This Woman With Dense Breasts Receive Supplemental Breast Cancer Screening?: Grand Rounds Discussion From Beth Israel Deaconess Medical Center

Breast cancer will develop in 12% of women during their lifetime and is the second leading cause of cancer death among U.S. women. Mammography is the most commonly used tool to screen for breast cancer. Considerable uncertainty exists regarding the age at which to begin screening and the optimal screening interval. Breast density is a risk factor for breast cancer. In addition, for women with dense breasts, small tumors may be missed on mammography and the sensitivity of screening is diminished. At the time of publication, 35 states had passed laws mandating that breast density be reported in the letters that radiologists send to women with their mammogram results. The mandated language may be challenging for patients to understand, and such reporting may increase worry for women who are told that their risk for breast cancer is higher than average on the basis of breast density alone. The U.S. Preventive Services Task Force and the American College of Radiology (ACR) have each issued guidelines that address breast cancer screening for women with dense breasts. Both organizations found insufficient evidence to recommend for or against magnetic resonance screening, whereas the ACR advises consideration of ultrasonography for supplemental screening. In this Beyond the Guidelines, 2 experts-a radiologist and a general internist-discuss these controversies. In particular, the discussants review the role of supplemental breast cancer screening, including breast ultrasonography or magnetic resonance imaging for women with dense breasts. Finally, the experts offer specific advice for a patient who finds her mammography reports confusing.

American College of Radiology Accreditation, Performance Metrics, Reimbursement, and Economic Considerations in Breast MR Imaging

Accreditation through the American College of Radiology (ACR) Breast Magnetic Resonance Imaging Accreditation Program is necessary to qualify for reimbursement from Medicare and many private insurers and provides facilities with peer review on image acquisition and clinical quality. Adherence to ACR quality control and technical practice parameter guidelines for breast MR imaging and performance of a medical outcomes audit program will maintain high-quality imaging and facilitate accreditation. Economic factors likely to influence the practice of breast MR imaging include cost-effectiveness, competition with lower-cost breast-imaging modalities, and price transparency, all of which may lower the cost of MR imaging and allow for greater utilization.

Overdiagnosis in primary care: framing the problem and finding solutions

Overdiagnosis, is defined as the diagnosis of a condition that, if unrecognized, would not cause symptoms or harm a patient during his or her lifetime, and it is increasingly acknowledged as a consequence of screening for cancer and other conditions. Because preventive care is a crucial component of primary care, which is delivered to the broad population, overdiagnosis in primary care is an important problem from a public health perspective and has far reaching implications. The scope of overdiagnosis as a result of services delivered in primary care is unclear, though overdiagnosis of indolent breast, prostate, thyroid, and lung cancers is well described and overdiagnosis of chronic kidney disease, depression, and attention-deficit/hyperactivity disorder is also recognized. However, overdiagnosis is a known consequence of all screening and can be assumed to occur in many more clinical contexts. Overdiagnosis can harm patients by leading to overtreatment (with associated potential toxicities), diagnosis related anxiety or depression, and labeling, or through financial burden. Many entrenched factors facilitate overdiagnosis, including the growing use of advanced diagnostic technology, financial incentives, a medical culture that encourages greater use of tests and treatments, limitations in the evidence that obscure the understanding of diagnostic utility, use of non-beneficial screening tests, and the broadening of disease definitions. Efforts to reduce overdiagnosis are hindered by physicians' and patients' lack of awareness of the problem and by confusion about terminology, with overdiagnosis often conflated with related concepts. Clarity of terminology would facilitate physicians' understanding of the problem and the growth in evidence regarding its prevalence and downstream consequences in primary care. It is hoped that international coordination regarding diagnostic standards for disease definitions will also help minimize overdiagnosis in the future.

Oral Administration and Detection of a Near-Infrared Molecular Imaging Agent in an Orthotopic Mouse Model for Breast Cancer Screening

Molecular imaging is advantageous for screening diseases such as breast cancer by providing precise spatial information on disease-associated biomarkers, something neither blood tests nor anatomical imaging can achieve. However, the high cost and risks of ionizing radiation for several molecular imaging modalities have prevented a feasible and scalable approach for screening. Clinical studies have demonstrated the ability to detect breast tumors using nonspecific probes such as indocyanine green, but the lack of molecular information and required intravenous contrast agent does not provide a significant benefit over current noninvasive imaging techniques. Here we demonstrate that negatively charged sulfate groups, commonly used to improve solubility of near-infrared fluorophores, enable sufficient oral absorption and targeting of fluorescent molecular imaging agents for completely noninvasive detection of diseased tissue such as breast cancer. These functional groups improve the pharmacokinetic properties of affinity ligands to achieve targeting efficiencies compatible with clinical imaging devices using safe, nonionizing radiation (near-infrared light). Together, this enables development of a “disease screening pill” capable of oral absorption and systemic availability, target binding, background clearance, and imaging at clinically relevant depths for breast cancer screening. This approach should be adaptable to other molecular targets and diseases for use as a new class of screening agents.

Analysis of utilization patterns and associated costs of the breast imaging and diagnostic procedures after screening mammography

BACKGROUND

Little data exist on real-world patterns and associated costs of downstream breast diagnostic procedures following an abnormal screening mammography or clinical exam.

OBJECTIVES

To analyze the utilization patterns in real-world clinical settings for breast imaging and diagnostic procedures, including the frequency and volume of patients and procedures, procedure sequencing, and associated health care expenditures.

MATERIALS AND METHODS

Using medical claims from 2011 to 2015 MarketScan Commercial and Medicare Databases, adult females with breast imaging/diagnostic procedures (diagnostic mammography, ultrasound, molecular breast imaging, tomosynthesis, magnetic resonance imaging, or biopsy) other than screening mammography were selected. Continuous health plan coverage without breast diagnostic procedures was required for ≥13 months before the first found breast diagnostic procedure (index event), with a 13-month post-index follow-up period. Key outcomes included diagnostic procedure volumes, sequences, and payments. Results reported descriptively were projected to provide US national patient and procedure volumes.

RESULTS

The final sample of 875,526 patients was nationally projected to 12,394,432 patients annually receiving 8,732,909 diagnostic mammograms (53.3% of patients), 6,987,399 breast ultrasounds (42.4% of patients), and 1,585,856 biopsies (10.3% of patients). Following initial diagnostic procedures, 49.4% had second procedures, 20.1% followed with third procedures, and 10.0% had a fourth procedure. Mean (SD) costs for diagnostic mammograms of US$349 ($493), ultrasounds US$132 ($134), and biopsies US$1,938 ($2,343) contributed US$3.05 billion, US$0.92 billion, and US$3.07 billion, respectively, to annual diagnostic breast expenditures estimated at US$7.91 billion.

CONCLUSION

The volume and expense of additional breast diagnostic testing, estimated at US$7.91 billion annually, underscores the need for technological improvements in the breast diagnostic landscape.

Extent and cost of inappropriate use of tumour markers in patients with pulmonary disease: a multicentre retrospective study in Shanghai, China

OBJECTIVES

The currently implemented healthcare reform in China requires substantial capital investment. Although overtreatment results in serious waste, inappropriate laboratory use is widespread, and overuse of tumour markers (TMs) has attracted increasing attention.

DESIGN

Retrospective study.

SETTING

The respiratory, thoracic surgery and oncology departments of three hospitals in Shanghai from 2014 to 2015.

PARTICIPANTS

Patients with chronic obstructive pulmonary disease (COPD) and primary bronchogenic lung cancer (PLC). Based on clinical guidelines and physician experience, the criteria of suitability of TM examinations were determined, and the number, cost and proportion of inappropriate TM requests were analysed.

RESULTS

The area under the receiver operating characteristic curve for carcinoembryonic antigen+cytokeratin fragment 21-1+squamous cell carcinoma antigen+neuron-specific enolase in patients with COPD and PLC was 0.813, in accordance with the cost-effectiveness principle, indicating good clinical and health economics values. In the 2706 patients, 12 496-16 956 (58.27%-79.06%) of TM requests were inappropriate. Furthermore, the involved expense was 650 200-1 014 156 yuan, accounting for 7.69%-12.00% of examination expenses and 1.35%-2.11% of hospitalisation costs.

CONCLUSIONS

We found that the inappropriate use of TMs was widespread for patients with pulmonary disease. Clinicians should use TMs strictly according to the guidelines to effectively manage laboratory resources and control costs.

Quantifying predictive capability of electronic health records for the most harmful breast cancer

Improved prediction of the "most harmful" breast cancers that cause the most substantive morbidity and mortality would enable physicians to target more intense screening and preventive measures at those women who have the highest risk; however, such prediction models for the "most harmful" breast cancers have rarely been developed. Electronic health records (EHRs) represent an underused data source that has great research and clinical potential. Our goal was to quantify the value of EHR variables in the "most harmful" breast cancer risk prediction. We identified 794 subjects who had breast cancer with primary non-benign tumors with their earliest diagnosis on or after 1/1/2004 from an existing personalized medicine data repository, including 395 "most harmful" breast cancer cases and 399 "least harmful" breast cancer cases. For these subjects, we collected EHR data comprised of 6 components: demographics, diagnoses, symptoms, procedures, medications, and laboratory results. We developed two regularized prediction models, Ridge Logistic Regression (Ridge-LR) and Lasso Logistic Regression (Lasso-LR), to predict the "most harmful" breast cancer one year in advance. The area under the ROC curve (AUC) was used to assess model performance. We observed that the AUCs of Ridge-LR and Lasso-LR models were 0.818 and 0.839 respectively. For both the Ridge-LR and Lasso-LR models, the predictive performance of the whole EHR variables was significantly higher than that of each individual component (p<0.001). In conclusion, EHR variables can be used to predict the "most harmful" breast cancer, providing the possibility to personalize care for those women at the highest risk in clinical practice.

Factors Associated with False Positive Results on Screening Mammography in a Population of Predominantly Hispanic Women

Background: Potential harms of screening mammography include false positive results, such as recall breast imaging or biopsies.Methods: We recruited women undergoing screening mammography at Columbia University Medical Center in New York, New York. They completed a questionnaire on breast cancer risk factors and permitted access to their medical records. Breast cancer risk status was determined using the Gail model and a family history screener. High risk was defined as a 5-year invasive breast cancer risk of ≥1.67% or eligible for BRCA genetic testing. False positive results were defined as recall breast imaging (BIRADS score of 0, 3, 4, or 5) and/or biopsies that did not yield breast cancer.Results: From November 2014 to October 2015, 2,361 women were enrolled and 2,019 were evaluable, of whom 76% were Hispanic and 10% non-Hispanic white. Fewer Hispanic women met high-risk criteria for breast cancer than non-Hispanic whites (18.0% vs. 68.1%), but Hispanics more frequently engaged in annual screening (71.9% vs. 60.8%). Higher breast density (heterogeneously/extremely dense vs. mostly fat/scattered fibroglandular densities) and more frequent screening (annual vs. biennial) were significantly associated with false positive results [odds ratio (OR), 1.64; 95% confidence interval (CI), 1.32-2.04 and OR, 2.18; 95% CI, 1.70-2.80, respectively].Conclusions: We observed that women who screened more frequently or had higher breast density were at greater risk for false positive results. In addition, Hispanic women were screening more frequently despite having a lower risk of breast cancer compared with whites.Impact: Our results highlight the need for risk-stratified screening to potentially minimize the harms of screening mammography. Cancer Epidemiol Biomarkers Prev; 27(4); 446-53. ©2018 AACR.

Mammography screening: A major issue in medicine

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.

Decommissioning care: The need for rigorous multifaceted evaluations of decisions to withdraw health services

In this Perspective on the two clinical trials of Terry Haines and colleagues that incrementally removed and reinstated allied healthcare services, Aziz Sheikh discusses the evidence base for the routine provision of such services.

Accuracy of Cyst Versus Solid Diagnosis in the Breast Using Quantitative Transmission (QT) Ultrasound

Rational and Objectives

This study aims to evaluate the diagnostic utility of breast imaging using transmission ultrasound. We present readers’ accuracy in determining whether a breast lesion is a cyst versus a solid using transmission ultrasound as an adjunct to mammography.

Materials and Methods

This retrospective multi-reader, multi-case receiver operating characteristic study included 37 lesions seen on mammography and transmission ultrasound. Cyst cases were confirmed as cysts using their appearance on handheld ultrasound. Solid cases were confirmed as solids with pathology results. Fourteen readers performed blinded, randomized reads with mammog-raphy + quantitative transmission scan images, assigning both a confidence score (0–100) and a binary classification of cyst or solid. A 95% percentile bootstrap confidence interval (CI) was computed for the readers’ mean receiver operating characteristic area, sensitivity, and specificity.

Results

Using the readers’ binary classification of cyst or solid lesions, the mean sensitivity and specificity were 0.933 [95% CI: 0.837, 0.995] and 0.858 [95% CI: 0.701, 0.985], respectively. When the readers’ confidence scores were used to distinguish a cyst versus solid, the mean receiver operating characteristic area was 0.920 [95% CI: 0.827, 0.985].

Conclusions

Transmission ultrasound can provide an accurate assessment of a cyst versus a solid lesion in the breast. Prospective clinical trials will further delineate the role of transmission ultrasound as an adjunct to mammography to increase specificity in breast evaluation.

The Effect of False-positive Mammograms on Antidepressant and Anxiolytic Initiation

BACKGROUND

Despite reported increases in anxiety following a false-positive mammogram, there is little evidence the effect rises to the clinical level of initiating medication.

OBJECTIVE

To analyze the effect of a false-positive mammogram on antidepressant or anxiolytic initiation and identify subpopulations most at risk.

SUBJECTS

MarketScan commercial and Medicaid claims databases used to identify women ages 40-64 undergoing screening mammography with no prior antidepressant or anxiolytic claims.

RESEARCH DESIGN

Using a retrospective cohort design, we estimated the effects of a false-positive relative to a negative mammogram on the likelihood of initiating antidepressants or anxiolytics using multivariate logistic models estimated separately by insurance type.

RESULTS

At 3 months after a false-positive mammogram, the relative risk (RR) for antidepressant or anxiolytic initiation was 1.19 [95% confidence interval (CI), 1.06-1.31] for the commercially insured and 1.13 (95% CI, 0.96-1.29) in the Medicaid population. In addition, 4 subgroups were at particularly elevated risk: commercially insured women ages 40-49 (RR=1.33; 95% CI, 1.13-1.54) or whose false-positive required multiple tests to resolve (RR=1.37; 95% CI, 1.17-1.57), included a biopsy (RR=1.68; 95% CI, 1.18-2.17), or whose resolution took >1 week (RR=1.21; 95% CI, 1.07-1.34).

CONCLUSIONS

False-positive mammograms were associated with significant increases in antidepressant or anxiolytic imitation among the commercially insured. Follow-up resources may be particularly beneficial for cases taking longer to resolve and involving biopsies or multiple tests. The results highlight the need to resolve false-positives quickly and effectively and to monitor depressive symptoms following a positive result.

Impact of extending screening mammography to older women: Information to support informed choices

From 2013 through 2017, the Australian national breast cancer screening programme is gradually inviting women aged 70-74 years to attend screening, following a policy decision to extend invitations to older women. We estimate the benefits and harms of the new package of biennial screening from age 50-74 compared with the previous programme of screening from age 50-69. Using a Markov model, we applied estimates of the relative risk reduction for breast cancer mortality and the risk of overdiagnosis from the Independent UK Panel on Breast Cancer Screening review to Australian breast cancer incidence and mortality data. We estimated screening specific outcomes (recalls for further imaging, biopsies, false positives, and interval cancer rates) from data published by BreastScreen Australia. When compared with stopping at age 69, screening 1,000 women to age 74 is likely to avert one more breast cancer death, with an additional 78 women receiving a false positive result and another 28 women diagnosed with breast cancer, of whom eight will be overdiagnosed and overtreated. The extra 5 years of screening results in approximately 7 more overdiagnosed cancers to avert one more breast cancer death. Thus extending screening mammography in Australia to older women results in a less favourable harm to benefit ratio than stopping at age 69. Supporting informed decision making for this age group should be a public health priority.

The Breast Cancer Screening "Arcade" and the "Whack-A-Mole" Efforts to Reduce Access to Screening

The effort to reduce access to breast cancer screening has been going on for decades. As each piece of misinformation has been published, scientific responses have exposed the fallacies, but then new "alternative facts" are generated. The effort has been compared to the arcade game "Whack-a-Mole" in which one false argument is addressed only to have a new one "pop up" to replace it. This has ranged from the false claim that early detection would have no effect on breast cancer, to the fallacious idea that early detection was leading to early deaths among young women, to the more recent false suggestion that tens of thousands of breast cancers found by mammography would disappear if left undetected. The following is a short review of a number of nonscientifically derived "Moles" that have been "Whacked" by science.

Breast cancer screening in patients with cancers other than breast

BACKGROUND

Screening mammography can detect early breast cancers and reduce subsequent cancer mortality. However, there is a lack of consensus as to when to discontinue screening. The absence of clear-cut guidelines on when not to screen means that many patients with advanced malignancies continue screening despite unclear benefit.

METHODS

We performed a retrospective cohort study of female patients diagnosed with a non-breast malignancy to explore the incidence and effects of screening mammography. Female patients diagnosed with a non-breast malignancy stage II or higher between 2007 and 2012 were identified through the Vermont Cancer Registry and cross-referenced with mammography screening logs from January 1, 2007 to September 30, 2014. Additional data were collected through chart review, in May 2016.

RESULTS

Twenty-six percent of women (398/1501) with a stage II or greater cancer (other than breast) diagnosed between 2007 and 2012 had a screening mammogram within the first 5 years of their diagnosis. Of these 398 women, 193 (48.5%) were alive without cancer, 132 (33.2%) had died, and 73 (18.3%) were alive with cancer at the time of chart review. Of those who died, 84 (63.6%) had a stage III or IV cancer. Eighteen (4.5%) had a breast biopsy following a screening mammogram suspicious for cancer, resulting in 13 (3.3%) benign diagnoses and 5 (1.3%) breast cancer diagnoses. No patient died of breast cancer.

CONCLUSIONS

Except for highly curable cancers, female patients diagnosed with an advanced non-breast malignancy experienced mortality that outweighs a breast cancer mortality benefit from screening mammography as estimated from prior studies.

Ethics of the Physician's Role in Health-Care Cost Control: AOA Critical Issues

The United States health-care expenditure is rising precipitously. The Congressional Budget Office has estimated that, in 2025, at our current rate of increased spending, 25% of the gross domestic product will be allocated to health care. Our per-capita spending on health care also far exceeds that of any other industrialized country. Health-care costs must be addressed if our country is to remain competitive in the global marketplace and to maintain its financial solvency. If unchecked, the uncontrolled rise in health-care expenditures will not only affect our capacity to provide our patients with high-quality care but also threaten the ability of our nation to compete economically on the global stage. This is not hyperbole but fiscal reality.As physicians, we are becoming increasingly familiar with the economics impacting health-care policy. Thus, we are in a unique position to control the cost of health care. This includes an increased reliance on creating and adhering to evidence-based guidelines. We can do this and still continue to respect the primacy of patient welfare and the right of patients to act in their own self-interest. However, as evidenced by the use of high-volume centers of excellence, each strategy adapted to control costs must be vetted and must be monitored for its unintended ethical consequences.The solution to this complex problem must involve the input of all of the health-care stakeholders, including the patients, payers, and providers. Physicians ought to play a role in designing and executing a remedy. After all, we are the ones who best understand medicine and whose moral obligation is to the welfare of our patients.

The Effect of Treatment Advances on the Mortality Results of Breast Cancer Screening Trials: A Microsimulation Model

BACKGROUND

Mammography trials, which are the primary sources of evidence for screening benefit, were conducted decades ago. Whether advances in systemic therapies have rendered previously observed benefits of screening less significant is unknown.

OBJECTIVE

To compare the outcomes of breast cancer screening trials had they been conducted using contemporary systemic treatments with outcomes of trials conducted with previously used treatments.

DESIGN

Computer simulation model of 3 virtual screening trials with similar reductions in advanced-stage cancer cases but reflecting treatment patterns in 1975 (prechemotherapy era), 1999, or 2015 (treatment according to receptor status).

DATA SOURCES

Meta-analyses of screening and treatment trials; study of dissemination of primary systemic treatments; SEER (Surveillance, Epidemiology, and End Results) registry.

TARGET POPULATION

U.S. women aged 50 to 74 years.

TIME HORIZON

10 and 25 years.

PERSPECTIVE

Population.

INTERVENTION

Mammography, chemotherapy, tamoxifen, aromatase inhibitors, and trastuzumab.

OUTCOME MEASURES

Breast cancer mortality rate ratio (MRR) and absolute risk reduction (ARR) obtained by the difference in cumulative breast cancer mortality between control and screening groups.

RESULTS OF BASE-CASE ANALYSIS

At 10 years, screening in a 1975 trial yielded an MRR of 90% and an ARR of 5 deaths per 10,000 women. A 2015 screening trial yielded a 10-year MRR of 90% and an ARR of 3 deaths per 10,000 women.

RESULTS OF SENSITIVITY ANALYSIS

Greater reductions in advanced-stage disease yielded a greater screening effect, but MRRs remained similar across trials. However, ARRs were consistently lower under contemporary treatments. When contemporary treatments were available only for early-stage cases, the MRR was 88%.

LIMITATION

Disease models simplify reality and cannot capture all breast cancer subtypes.

CONCLUSION

Advances in systemic therapies for breast cancer have not substantively reduced the relative benefits of screening but have likely reduced the absolute benefits because of their positive effect on breast cancer survival.

PRIMARY FUNDING SOURCE

University of Washington and National Cancer Institute.

Four Principles to Consider Before Advising Women on Screening Mammography

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.