Were our estimates of overdiagnosis with mammography screening in the United States "based on faulty science"?

Screening Mammography Among Older Women: A Review of United States Guidelines and Potential Harms

In the United States, older women (aged ≥65 years) continue to receive routine screening mammography surveillance, despite limited evidence supporting the benefits to this subpopulation. This article reviews screening mammography guidelines and the potential harms of such screening for older women in the United States. Published guidelines and recommendations on screening mammography for older women from professional medical societies and organizations in the United States were reviewed from the mid-20th century to present. Observational data were then synthesized to present the documented harms from screening mammography among older women. In 1976, the American Cancer Society recommended to screen all women aged ≥40 years with no upper age limit. With time, other major U.S. medical societies adopted their own screening guidelines without a consensus on age of screening cessation. A population-wide screening effort has largely continued without an upper age limit and with it, a growing body of literature on the harms of screening older women. Reported harms from screening mammography procedures have included physical pain, psychological distress, excessive use of health services from overdiagnoses/false positives, and undue financial expenses. These costs are particularly pronounced among special populations with limited life expectancies such as those of very advanced age ≥80 years, long-term nursing home residents, and the cognitively impaired. When potential harms, remaining life years, and the viability of available treatments are considered, the burdens of screening mammography often outweigh the benefits for older women. For some cases, an individualized approach to recommendations would be appropriate. National guidelines should be updated to provide clear guidance for screening women of advanced age, especially those in special populations with limited life expectancies.

Evaluation of the "Angelina Jolie Effect" on Screening Mammography Utilization in an Academic Center

PURPOSE

The aim of this study was to understand the impact on screening mammography at our institution, comparing weekly utilization in the 2 years before and the 2 years after Ms Angelina Jolie disclosed in the New York Times on May 13, 2013, that she had had a prophylactic double mastectomy.

METHODS

All 48,110 consecutive screening mammograms conducted at our institution between May 16, 2011, and May 16, 2015, were selected from our electronic medical record system. We used interrupted time series statistical models and graphical methods on utilization data to understand utilization changes before and after Ms Jolie's news.

RESULTS

The graphed trend of weekly screening mammogram utilization failed to show changes around the time of interest. Analytical models and statistical tests also failed to show a step change increase or acceleration of utilization around May 2013. However, graphical and time series analyses showed a flattening of utilization in the middle of 2014.

CONCLUSIONS

In our well-powered analysis in a large regional breast imaging center, we found no support for the hypothesis that this celebrity news drove increased screening.

Breast cancer screening in Brazil. Barriers related to the health system

Objective:

Identify factors related to the health system that lead to a late diagnosis of breast cancer in Brazil.

Method:

We performed a systematic review in the PubMed and LILACS databases using as keywords "Breast cancer," "system of health" and "Brazil or Brasil." We evaluated the content of the articles using the PRISMA methodology based on PICTOS. The final date was 12/16/2015. We were able to identify 94 publications in PubMed and 43 publications in LILACS. After assessing the title and summary, and excluding 21 repeated publications, we selected 51 publications for full evaluation. At this stage, we excluded 21 articles, with 30 publications remaining for study.

Results:

The population coverage is low, and there are problems related to the quality of mammography. Patients with lower income, nonwhite and less educated are more vulnerable. We observed punctual and initial experiences in breast cancer screening. Diagnosis and treatment flows must be improved. The inequality in mortality reflects the differences related to screening structure and treatment. Better results are observed in well-structured services.

Conclusion:

There are several barriers in the health system leading to advanced stage at diagnosis and limiting the survival outcomes. The establishment of a rapid and effective order for diagnosis and treatment, based on hierarchical flow, are important steps to be improved in the public health context.

The WISDOM Study: breaking the deadlock in the breast cancer screening debate

There are few medical issues that have generated as much controversy as screening for breast cancer. In science, controversy often stimulates innovation; however, the intensely divisive debate over mammographic screening has had the opposite effect and has stifled progress. The same two questions—whether it is better to screen annually or bi-annually, and whether women are best served by beginning screening at 40 or some later age—have been debated for 20 years, based on data generated three to four decades ago. The controversy has continued largely because our current approach to screening assumes all women have the same risk for the same type of breast cancer. In fact, we now know that cancers vary tremendously in terms of timing of onset, rate of growth, and probability of metastasis. In an era of personalized medicine, we have the opportunity to investigate tailored screening based on a woman’s specific risk for a specific tumor type, generating new data that can inform best practices rather than to continue the rancorous debate. It is time to move from debate to wisdom by asking new questions and generating new knowledge. The WISDOM Study (Women Informed to Screen Depending On Measures of risk) is a pragmatic, adaptive, randomized clinical trial comparing a comprehensive risk-based, or personalized approach to traditional annual breast cancer screening. The multicenter trial will enroll 100,000 women, powered for a primary endpoint of non-inferiority with respect to the number of late stage cancers detected. The trial will determine whether screening based on personalized risk is as safe, less morbid, preferred by women, will facilitate prevention for those most likely to benefit, and adapt as we learn who is at risk for what kind of cancer. Funded by the Patient Centered Outcomes Research Institute, WISDOM is the product of a multi-year stakeholder engagement process that has brought together consumers, advocates, primary care physicians, specialists, policy makers, technology companies and payers to help break the deadlock in this debate and advance towards a new, dynamic approach to breast cancer screening.

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 developing countries

Developing countries have limited healthcare resources and use different strategies to diagnose breast cancer. Most of the population depends on the public healthcare system, which affects the diagnosis of the tumor. Thus, the indicators observed in developed countries cannot be directly compared with those observed in developing countries because the healthcare infrastructures in developing countries are deficient. The aim of this study was to evaluate breast cancer screening strategies and indicators in developing countries. A systematic review and the Population, Intervention, Comparison, Outcomes, Timing, and Setting methodology were performed to identify possible indicators of presentation at diagnosis and the methodologies used in developing countries. We searched PubMed for the terms "Breast Cancer" or "Breast Cancer Screening" and "Developing Country" or "Developing Countries". In all, 1,149 articles were identified. Of these articles, 45 full articles were selected, which allowed us to identify indicators related to epidemiology, diagnostic intervention (diagnostic strategy, diagnostic infrastructure, percentage of women undergoing mammography), quality of intervention (presentation of symptoms at diagnosis, time to diagnosis, early stage disease), comparisons (trend curves, subpopulations at risk) and survival among different countries. The identification of these indicators will improve the reporting of methodologies used in developing countries and will allow us to evaluate improvements in public health related to breast cancer.

Impact of screening mammography on breast cancer mortality

The degree to which observed reductions in breast cancer mortality is attributable to screening mammography has become increasingly controversial. We examined this issue with three fundamentally different approaches: (i) Chronology--the temporal relationship of the onset of breast cancer mortality decline and the national implementation of screening mammography; (ii) Magnitude--the degree to which breast cancer mortality declined relative to the amount (penetration) of screening mammography; (iii) Analogy--the pattern of mortality rate reductions of other cancers for which population screening is not conducted. Chronology and magnitude were assessed with data from Europe and North America, with three methods applied to magnitude. A comparison of eight countries in Europe and North America does not demonstrate a correlation between the penetration of national screening and either the chronology or magnitude of national breast cancer mortality reduction. In the United States, the magnitude of the mortality decline is greater in the unscreened, younger women than in the screened population and regional variation in the rate of breast cancer mortality reduction is not correlated with screening penetrance, either as self-reported or by the magnitude of screening-induced increase in early-stage disease. Analogy analysis of United States data identifies 14 other cancers with a similar distinct onset of mortality reduction for which screening is not performed. These five lines of evidence from three different approaches and additional observations discussed do not support the hypothesis that mammography screening is a primary reason for the breast cancer mortality reduction in Europe and North America.

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.

Screening mammography: update and review of publications since our report in the New England Journal of Medicine on the magnitude of the problem in the United States

RATIONALE AND OBJECTIVES

After a half century of clinical trials, expansive observations, vigorous advocacy and debate, screening mammography could not be in a more controversial condition, especially the potential harm of overdiagnosis. Despite a simple rationale (catch the cancer early and either prevent death or at least decrease the amount of therapy needed for cure), the estimates to date of overdiagnosis rates are conflicting and the interpretations complex.

MATERIALS AND METHODS

Since the author's 2012 publication in the New England Journal of Medicine (NEJM), the peer-reviewed publications on overdiagnosis caused by screening mammography are reviewed and the NEJM analyses updated with three additional calendar years of results.

RESULTS

The recent peer-reviewed medical literature on screening mammography induced overdiagnosis of breast cancer has increased exponentially, nearly 10-fold in 10 years. The average estimate of overdiagnosis is about 30%, but the range extends from 0% to 70+%. An update of the NEJM report estimates that in the US, 78,000 women and 30%-31% of those diagnosed with breast cancer at the age of 40 years or older during 2011 were overdiagnosed.

CONCLUSIONS

Until we have better screening procedures that identify who really has cancer and needs to be treated, the risk of overdiagnosis relative to the benefit of screening merits more effective public and professional education. Radiologists, pathologists, and other professionals involved with screening mammography should recognize that the potential harm of overdiagnosis is downplayed or not discussed with the patient and family, despite agreement that the objective is informed choice.

Enhancing cancer care in areas of limited resources: our next steps

In-depth knowledge of local conditions is necessary in order to enhance care in low- and middle-income countries. In this review we discuss: improving cancer diagnosis, optimizing patient management, increasing health awareness, prevention, early detection, eradication of causative infectious diseases and agents, tobacco control, healthy diets and lifestyles, availability of diagnostic methods, easy access to care, affordable costs, improving infrastructures, quality care measures, implementing and adapting guidelines, multidisciplinary management, supportive and survivorship care, research and optimization of medical school curriculum and training in oncology. Establishment of national cancer control plans by policy makers, physician societies, medical schools, and patient advocates is recommended. We will review evidence and controversies, and outline the next steps needed to prevent cancer and enhance care of cancer patients in LMICs.

An open letter to panels that are deciding guidelines for breast cancer screening

Panels are presently reviewing breast cancer screening guidelines. It is critical that they understand which publications are scientifically valid, and which analyses are methodologically flawed and not valid. The scientific evidence clearly supports annual mammography screening beginning at the age of 40. The analyses that suggest that screening leads to overdiagnosis of invasive breast cancers are flawed and incorrect. There is little if any overdiagnosis of these cancers. The vast majority of breast cancers occur in women who are not at elevated risk so that excluding them from screening and only screening high risk women will deny the benefits of early detection to most women who develop breast cancer. Guidelines panels should not make decisions that exclude women from screening. Women should be provided with accurate information so that they can make informed decisions and have unimpeded access to screening if that is their preference.

Overdiagnosis: epidemiologic concepts and estimation

Overdiagnosis of thyroid cancer was propounded regarding the rapidly increasing incidence in South Korea. Overdiagnosis is defined as 'the detection of cancers that would never have been found were it not for the screening test', and may be an extreme form of lead bias due to indolent cancers, as is inevitable when conducting a cancer screening programme. Because it is solely an epidemiological concept, it can be estimated indirectly by phenomena such as a lack of compensatory drop in post-screening periods, or discrepancies between incidence and mortality. The erstwhile trials for quantifying the overdiagnosis in screening mammography were reviewed in order to secure the data needed to establish its prevalence in South Korea.

International screening and early detection of breast cancer: resource-sensitive, age- and risk-specific guidelines

SUMMARY 

In this article we review the evidence and current controversies surrounding screening and early detection of breast cancer, from the initially positive age-specific randomized trials of the 1970s and 1980s, to the 2009 USPSTF recommendations, 2013 interpretation of SEER data, 2014 Canadian Study updates, and BHGI resource-sensitive guidelines, as well as the few reports available from emerging countries. We will also discuss the burden of breast cancer in low- and middle- income countries with rising incidence rates and advanced stages at presentation, the need for increasing awareness and downstaging of disease. We will discuss the data putting it in perspective for general guidelines for the international scene, and suggest adoption of evidence-based resource-sensitive and risk-specific guidelines, with less reliance on broad age-specific guidelines.