The Little Known Truth About Mammograms

Adam Ruins The Hospital – Season 2 | Ep 203, 2017

Mammograms might be able to detect cancer but they can’t tell the difference between different types. Turns out, mammograms can harm and save much fewer lives than you think.

Breast cancer screening not associated with a reduction in the incidence of advanced cancer

Mammograms tied to overdiagnosis of breast cancer

The current study offers fresh evidence linking routine screening to over-diagnosis of non-aggressive tumors because it compares outcomes over a single time period in two regions of Denmark – one that offered biennial mammography for women aged 50 to 69 and one that didn’t.

January 2017 Study Abstract

Effective breast cancer screening should detect early-stage cancer and prevent advanced disease.

To assess the association between screening and the size of detected tumors and to estimate overdiagnosis (detection of tumors that would not become clinically relevant).

Cohort study.

Breast Cancer Screening in Denmark: A Cohort Study of Tumor Size and Overdiagnosis, Annals of Internal Medicine, DOI: 10.7326/M16-0270, 10 JANUARY 2017.

Philips Mammography Truck, Brazil via philips_newscenter.

Denmark from 1980 to 2010.

Women aged 35 to 84 years.

Screening programs offering biennial mammography for women aged 50 to 69 years beginning in different regions at different times.

Trends in the incidence of advanced (>20 mm) and nonadvanced (≤20 mm) breast cancer tumors in screened and nonscreened women were measured. Two approaches were used to estimate the amount of overdiagnosis: comparing the incidence of advance and nonadvanced tumors among women aged 50 to 84 years in screening and nonscreening areas; and comparing the incidence for nonadvanced tumors among women aged 35 to 49, 50 to 69, and 70 to 84 years in screening and nonscreening areas.

Screening was not associated with lower incidence of advanced tumors. The incidence of nonadvanced tumors increased in the screening versus prescreening periods (incidence rate ratio, 1.49 [95% CI, 1.43 to 1.54]). The first estimation approach found that 271 invasive breast cancer tumors and 179 ductal carcinoma in situ (DCIS) lesions were overdiagnosed in 2010 (overdiagnosis rate of 24.4% [including DCIS] and 14.7% [excluding DCIS]). The second approach, which accounted for regional differences in women younger than the screening age, found that 711 invasive tumors and 180 cases of DCIS were overdiagnosed in 2010 (overdiagnosis rate of 48.3% [including DCIS] and 38.6% [excluding DCIS]).

Regional differences complicate interpretation.

Breast cancer screening was not associated with a reduction in the incidence of advanced cancer. It is likely that 1 in every 3 invasive tumors and cases of DCIS diagnosed in women offered screening represent overdiagnosis (incidence increase of 48.3%).

Regular Mammograms Risk-Benefit Characterization Theater

Breast-Cancer and Mammography : Consider the Pros and Cons

How Tiny Are Benefits From Many Tests And Pills? Researchers Paint A Picture

Mammograms are said to cut the risk of dying from breast cancer by as much as 20 percent ; some researchers want people to question that kind of thinking.

More Information

France: how to end breast cancer screening

The French national breast screening program is to be “radically revised”

In view of controversies surrounding the effectiveness and consequences of breast screening, the French Minister for Health asked the French National Cancer Institute (INCa) to organize a broad public and scientific consultation on breast cancer screening. During one year, all stakeholders on breast screening ranging from citizens, patient’s organisations and charities to health professionals, screening experts, and governmental institutions had an opportunity to express their opinion on the benefits and on the harms of breast screening as well as on the way this screening is organised in France. The consultation report was publicly available on September 30th, 2016.

Reduction in breast cancer deaths is due to treatment not screening, finds study, The BMJ, 355/bmj.i5544/rr-1, 13 October 2016.

The consultation report concludes that there is no scientific consensus about the benefits and risks of mammographic screening. It regrets the absence of sound epidemiological studies on the impact of breast screening in France. It expresses deep concerns about the

“malfunctions anomalies in the current organization of screening and the consequences it engenders: unequal access; lack of understanding of key concepts underpinning screening by most stakeholders; confusion between primary prevention, screening and early diagnosis; lack of information [of women] on risks and uncertainties of screening (…); lack of involvement of general practitioners (…); misleading and outrageous pink October marketing (…); doubts on the efficiency of some therapeutic strategies, etc.”

The report recommends that the information to women and the information and training of health professionals include a complete, clear and neutral information on the benefit and harm balance of participation to screening, with a depiction of reasons underlying the on-going scientific controversy.

It recommends discontinuing the reimbursement of mammographic screening in women less than 50 years of age at average risk of breast cancer. For healthy women over 50 years of age, the report recommends to take steps towards stratification of screening according to personal risk factors. Screening should be individualised, with the implication that women with low risk profile should not be offered mammographic screening. It also recommends that GPs should be integral part of the screening approach.

The options being considered for the future of screening are as follows:

  • Scenario 1: the end of organized screening, with the relevance of mammograms being evaluated in the context of an individual doctor patient relationship.
  • Scenario 2: the end of organized screening as now practiced, and the establishment of a new, radically altered form of organized screening. [i.e., much reduced]

The report is confident that

“the implementation of these recommendations should significantly improve the current situation, which currently does not meet the minimum requirements in terms of scientific validity and of information allowing women at average risk of breast cancer to take decisions”

The consultation report implicitly raises the question of whether the INCa would be the best placed for implementing recommendations and bring the radical changes in the breast screening programme. As a matter of fact, the INCa efforts have largely concentrated on maximizing participation to screening, the consequence of which has been the broadcasting of oversimplified messages insisting on the health benefits of screening while downplaying the undesirable effects like the overdiagnosis. In this regard, the INCa has backed the policy of financial incentives to GPs linked to their ability to convince women to participate to screening. Our opinion is that a neutral body should shape the breast screening programme, determine its main working procedures, and formulate the information to women and to health professionals. The members of this neutral body should have no academic or financial conflict of interest in relation to breast screening, and should not be involved in its implementation. We believe that such a move would be respectful of the consultation report conclusions and contribute to empowering women to decide on their participation to breast screening.

Jean Doubovetzky
Emilie Franzin
Marc Gourmelin
Philippe Nicot

On behalf of The Cancer-rose group.

Breast-Cancer Tumor Size, Overdiagnosis, and Mammography Screening Effectiveness

NEJM Screening Mammograms, Analysis by Dr. H. Gilbert Welch

Dr. H. Gilbert Welch gives us a brief explanation of the findings of the New England Journal of Medicine article “Breast Cancer Tumor Size, Overdiagnosis, and Mammography Screening Effectiveness“, October 13, 2016.

Study Abstract

The goal of screening mammography is to detect small malignant tumors before they grow large enough to cause symptoms. Effective screening should therefore lead to the detection of a greater number of small tumors, followed by fewer large tumors over time.

We used data from the Surveillance, Epidemiology, and End Results (SEER) program, 1975 through 2012, to calculate the tumor-size distribution and size-specific incidence of breast cancer among women 40 years of age or older. We then calculated the size-specific cancer case fatality rate for two time periods: a baseline period before the implementation of widespread screening mammography (1975 through 1979) and a period encompassing the most recent years for which 10 years of follow-up data were available (2000 through 2002).

After the advent of screening mammography, the proportion of detected breast tumors that were small (invasive tumors measuring

Although the rate of detection of large tumors fell after the introduction of screening mammography, the more favorable size distribution was primarily the result of the additional detection of small tumors. Women were more likely to have breast cancer that was overdiagnosed than to have earlier detection of a tumor that was destined to become large. The reduction in breast cancer mortality after the implementation of screening mammography was predominantly the result of improved systemic therapy.

If screening had been a drug, it would have been withdrawn from the market

Which country will be first to stop mammography screening?

Key points

  • Screening with mammography does not reduce the occurrence of advanced cancers.
  • Rigorous observational studies in Europe have failed to find an effect of mammography screening.
  • Mammography screening produces patients with breast cancer from among healthy women and increases the number of mastectomies performed.
  • The most effective method we have to reduce the occurrence of breast cancer is to stop screening.

Time to stop mammography screening?

The Canadian Task Force on Preventive Health Care should be congratulated for its new recommendations on screening for breast cancer in women at average risk aged 40–74 years. These guidelines are more balanced and more in accordance with the evidence than any previous recommendations.

The recommendations against routine clinical breast examinations, breast self-examinations and magnetic resonance imaging to screen for breast cancer in this age and risk group are all straightforward.

The recommendations on mammography screening are even more conservative than the change in policy suggested by the US Preventive Services Task Force in 2009, which created an uproar in the United States from people interested in maintaining the status quo. The new Canadian guidelines are appropriately cautious, advising against routinely screening women aged 40–49 years. The task force recommends screening women aged 50–69 years every two to three years, although it admits that this is a weak recommendation based on moderate-quality evidence, and screening women aged 70–74 years on the same schedule based on low-quality evidence. The task force also suggests that women who do not place a high value on a small reduction in breast cancer mortality, and who are concerned with false-positive results on mammography and overdiagnosis, may decline screening.

These guidelines are an important step in the right direction, away from the prevailing attitude that a woman who does not undergo screening is irresponsible. Recent research even suggests that it may be most wise to avoid screening altogether, at any age, as outlined below.

The Canadian Task Force on Preventive Health Care decided not to include observational studies in its systematic review unless they were needed to elucidate the harms of screening or the values and preferences of patients. However, important observational studies have been published in recent years, without which a systematic review would be incomplete. These observational studies have been discussed elsewhere and have also been included in an update (currently submitted for publication) of our 2009 Cochrane review of mammography screening.

Doubtful effect of screening

Time to stop mammography screening?; National Institutes of Health PMC3225414 183(17): 1957–1958, Nov 22 2011.

Programming a latest-gen mammography station, nicoyogui.

If screening does not reduce the occurrence of advanced cancers, it does not work. A systematic review of studies from seven countries showed that, on average, the rate of malignant tumours larger than 20 millimetres was not affected by screening. Because the size of a tumour is linearly correlated to the risk of metastasis, this result is evidence against an effect of screening.

Denmark has a unique control group within its population — only 20% of its population was screened during a 17-year period. The annual decrease in breast cancer mortality in the relevant age group (55–74 years) and period was 1% in the areas with screening and 2% in the non-screened areas.Among women who were too young to benefit from screening, the decreases were larger (5% for screened areas, 6% for unscreened areas). Similar results have been reported from the United Kingdom, Sweden and Norway.

A study involving women from 30 European countries showed that the mean decrease in breast cancer mortality between 1989 and 2005 among women less than 50 years of age was 37%; the corresponding decrease was 21% among women aged 50–69 years. The declines began before the start of organized screening programs in many countries and are more likely explained by the introduction of tamoxifen. The introduction of tamoxifen could explain the larger decline seen among young women who often have estrogen-sensitive tumours.

Another study compared three pairs of similar neighbouring countries that had introduced screening 10–15 years apart. The pairs were Northern Ireland and the Republic of Ireland, the Netherlands and Belgium, and Sweden and Norway. There was no relation between start of screening and the reduction in breast cancer mortality.The fall in breast cancer mortality was about the same in all countries. Furthermore, the decline was also about the same as that seen in the United States, where screening started as early as in Sweden.

Screening seems to be ineffective in today’s world for two reasons. First, adjuvant therapy, such as tamoxifen and chemotherapy, is highly effective (even when the cancer has metastasized) but was not often used at the time of the old trials. Second, public awareness of breast cancer has increased, and women tend to see a doctor much earlier today when they have noticed something unusual in their breast. In Denmark, the average size of a tumour decreased by nine millimetres from 1979 to 1989, a reduction that occurred before screening started. In addition, this decrease was larger than the average difference in tumour size seen between screened and control groups in trials (5 mm), despite the tendency for small, overdiagnosed tumours to spuriously exaggerate the difference.

It has often been claimed that mammography screening reduces breast cancer mortality by 30%. However, thorough systematic reviews have estimated only a 15% reduction, and data on tumour size from the trials are compatible with only a 12% effect.This effect is similar to the results seen in the most reliable studies, which showed a 10% effect after 13 years.


Any possible effect of screening on breast cancer mortality must be marginal and could be counteracted by the life-shortening effect that radio-therapy and chemotherapy have when used in healthy women in whom breast cancer has been overdiagnosed (i.e., a diagnosis of breast cancer that would not have been made in the woman’s remaining life had she not undergone screening). The main effect of screening is to produce patients with breast cancer from among healthy women who would have remained free of breast disease for the rest of their lives had they not undergone screening. Compelling data from the US, Norway and Sweden show that most overdiagnosed tumours would have regressed spontaneously without treatment.  In addition, screening substantially increases the number of mastectomies performed, despite routine claims to the contrary by advocates of screening.

The best method we have to reduce the risk of breast cancer is to stop the screening program. This could reduce the risk by one-third in the screened age group, as the level of overdiagnosis in countries with organized screening programs is about 50%.

If screening had been a drug, it would have been withdrawn from the market. Thus, which country will be first to stop mammography screening?

Peter Gøtzsche, MD, 2011.

Should tomosynthesis and ultrasound be the primary screening modality in women with dense breasts?

Mammograms may be missing some breast cancers, study shows

image of 3D breast tomosynthesis mammography
Additional screening techniques can detect more cases of breast cancer in some women, researchers say. Photograph: Torin Halsey/AP: a radiologist compares an image from a mammogram with a 3D breast tomosynthesis mammography in Wichita Falls, Texas.


Adjunct Screening With Tomosynthesis or Ultrasound in Women With Mammography-Negative Dense Breasts: Interim Report of a Prospective Comparative Trial, American Society of Clinical Oncology, doi: 10.1200/JCO.2015.63.4147, March 9, 2016.

Debate on adjunct screening in women with dense breasts has followed legislation requiring that women be informed about their mammographic density and related adjunct imaging. Ultrasound or tomosynthesis can detect breast cancer (BC) in mammography-negative dense breasts, but these modalities have not been directly compared in prospective trials. We conducted a trial of adjunct screening to compare, within the same participants, incremental BC detection by tomosynthesis and ultrasound in mammography-negative dense breasts.

Patients and Methods
Adjunct Screening With Tomosynthesis or Ultrasound in Women With Mammography-Negative Dense Breasts is a prospective multicenter study recruiting asymptomatic women with mammography-negative screens and dense breasts. Eligible women had tomosynthesis and physician-performed ultrasound with independent interpretation of adjunct imaging. Outcome measures included cancer detection rate (CDR), number of false-positive (FP) recalls, and incremental CDR for each modality; these were compared using McNemar’s test for paired binary data in a preplanned interim analysis.

Among 3,231 mammography-negative screening participants (median age, 51 years; interquartile range, 44 to 78 years) with dense breasts, 24 additional BCs were detected (23 invasive): 13 tomosynthesis-detected BCs (incremental CDR, 4.0 per 1,000 screens; 95% CI, 1.8 to 6.2) versus 23 ultrasound-detected BCs (incremental CDR, 7.1 per 1,000 screens; 95% CI, 4.2 to 10.0), P = .006. Incremental FP recall occurred in 107 participants (3.33%; 95% CI, 2.72% to 3.96%). FP recall (any testing) did not differ between tomosynthesis (FP = 53) and ultrasound (FP = 65), P = .26; FP recall (biopsy) also did not differ between tomosynthesis (FP = 22) and ultrasound (FP = 24), P = .86.

Mammograms may be missing some breast cancers, study shows, theguardian, 9 March 2016.

The Adjunct Screening With Tomosynthesis or Ultrasound in Women With Mammography-Negative Dense Breasts’ interim analysis shows that ultrasound has better incremental BC detection than tomosynthesis in mammography-negative dense breasts at a similar FP-recall rate. However, future application of adjunct screening should consider that tomosynthesis detected more than 50% of the additional BCs in these women and could potentially be the primary screening modality.

USA: some insurers pay women to get frequent mammograms

Instead, employers and health plans should offer incentives that reward the use of evidence-based decision aids

image of Woman-and-Mammogram
How widespread is the practice of incentivizing mammograms? Image Jon Krause.
  • A 53-year-old woman on Medicaid in Washington State who has never had a mammogram elects to get one in return for a $15 gift card.
  • A 35-year-old woman in Florida chooses to get her first mammogram because her insurer, Aetna, offers a $50 payroll check.
  • In Iowa, a 46-year-old woman who has been getting mammograms every other year opts to get them annually because Wellmark Blue Cross Blue Shield will pay her $50 to do so.

All three of these women have average risk profiles, and none have family members with breast cancer. Who made the right choice?

It’s a trick question. The real question is whether employers and health plans should really be offering incentives to women to get frequent mammograms.

… continue reading:  Insurer Rewards Push Women Toward MammogramsNY Times, JAN. 18, 2016.

Au nom de tous les seins

Incertain dépistage organisé

Porté par des enjeux humains et de santé publique, le documentaire suit le parcours de quatre femmes confrontées, un jour, à la peur du cancer du sein. Leurs histoires sont le point de départ d’une enquête scientifique qui bouscule nos certitudes..

Tous les ans au mois d’octobre, la campagne pour le dépistage bat son plein. Mais depuis quelques années, la controverse monte:

En savoir plus

How invalid messages about screening mammography can be detrimental to women

Understanding the Harms and Benefits of Routine Breast Cancer Screening

Download and print a PDF – Understanding the Harms and Benefits of Routine Breast Cancer Screening.

This post content was published by APHA, the American Public Health Association: For science. For action. For health

The goal of breast cancer screening is to prevent women from dying from breast cancer, and for thirty years we have been told by industry that regular mammograms will save our lives. Current science shows that screening mammograms do not reduce the number of women who die from breast cancer and comes with significant harms including false positives, overdiagnosis and overtreatment. Many mainstream public health and breast cancer organizations have neglected to update their positions and educational materials with these evidence-based changes. How can we hold these national organizations accountable for pushing a scientifically invalid message?

Conveying information in an accessible and visually engaging way, the brochure, Should I Have A Mammogram: Understanding the Harms and Benefits of Routine Breast Cancer Screening, is designed to provide important evidence based information for women at “average risk”. As women evaluate their health decisions, they must have access to unbiased information, free from conflict of interest and without the heavy thumb of vested interests tipping the balance. Download and print a PDF.

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