One key detail you’re unlikely to see in news stories about mammography screening guidelines

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Alan Cassels is a pharmaceutical policy researcher at the University of Victoria, British Columbia, a journalist, and author of the The Cochrane Collaboration: Medicine’s Best-Kept Secret.

In mid-January, there was a flurry of news media activity focusing on breast cancer screening and the problem of overdiagnosis, particularly when breast tumors are benign but treated as if they were deadly.

Stories in Forbes​, NBC, USA Today, Medscape and Time Magazine covered a Danish study that found up to a third of breast cancers detected via mammography “would never have caused a noticeable health problem or led to death – and are therefore examples of overdiagnosis,” as Reuters put it.

While all these stories did a pretty good job of highlighting the changing landscape of recommendations, they tended to gloss over the very political nature of breast cancer screening, including who stands to gain financially from more aggressive screening and how those incentives may impact national screening recommendations in the U.S. and abroad. 

In the U.S., it is clear that our “pink ribbon” culture is wildly enamored with mammography, and relies heavily on the “early detection saves lives” meme that generates interest and donors. As a result, the money, reputations and infrastructure tied to mammography wield an undeniable influence on decision-making and health policies. And, expected growth in the mammography market–discussed in this recent market analysis–is high, even as some public health agencies are generally saying we should be more selective to whom we offer breast cancer screening.

Which groups endorse early mammography? And why?

So what’s a woman to do? That’s ultimately an individual decision, but here is one key detail you’re unlikely to see in news coverage: The U.S. groups that endorse early mammography–usually starting at age 40–are the same groups that benefit from revenues from the breast cancer industry, including the American College of Radiology (who owns the trademark for the Mammography Saves Lives campaign), and the National Breast Cancer Foundation. Companies involved include Siemens, which sponsors American Cancer Society’s Make Strides Against Breast Cancer campaign, and General Electric, which sponsors the American Breast Cancer Foundation. They are two of the main manufacturers of the devices used in mammography.

Meanwhile, independent groups, such as the United States Preventive Services Task Force (USPSTF), say that the net benefit is small in women over 40, and they recommend that women 50 to 74 have mammograms every two years. The USPSTF is made up of independent scientists who assess the value of screening, are not allowed to make financial arrangements with providers, and do not consider cost impact in their analysis. In Canada, the Canadian Task Force on Preventive Healthcare has similar recommendations to the USPSTF– but they were actually more aggressive in attempting to scale back the overuse of breast cancer screening.

Breast Cancer Action, an advocacy group in the U.S. which takes no donations from drug or device companies, is one of the more outspoken cancer charities and has produced solid, evidence-based recommendations on mammography.  Their 50+ recommendation jives with evidence that goes back as far 2002, when a Swedish meta-analysis of research published in the Lancet determined that there was unlikely to be any benefit in screening women under the age of 55.

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

Yet, the 40+ recommendations persists, even in the face of growing evidence that the benefits of starting at age 40 are small and the harms considerable. One provocative challenge was made in 2011 by Dr. Peter Gotzsche, head of the Nordic Cochrane Centre, and one of the world’s foremost experts on breast cancer screening. In an editorial in the Canadian Medical Association Journal titled “Time to Stop Mammography Screening?” he explained that “the best method we have to reduce the risk of breast cancer is to stop the screening program.” He added that the “level of overdiagnosis in countries with organized screening programs is about 50%.”  (While estimates differ, depending on how things are measured, the level of overdiagnosis found in the most recent Danish study was about 33%.)

Also, he added, “if screening had been a drug, it would have been withdrawn from the market. Thus, which country will be first to stop mammography screening?”

So far, “no one has abandoned breast screening yet. But independent panels in Switzerland and France have recommended their governments to do this,” said Karsten Jorgensen, the lead author of the Danish study (and a colleague of Peter Gotzsche). Both the Swiss and the French panels wanted to see new restrictions on mammography programs, and, for example, the Swiss board recommended that no new systematic mammography screening programs be introduced and that a time limit be placed on existing programs. 

No cancer screening has ever been shown to reduce overall mortality

Notably, Time Magazine mentioned the situation in other countries, telling readers that the French National Cancer Institute is set “to launch a year-long inquiry into how to improve screening, and the Swiss Medical Board now advises against routine mammogram screening for most women,” The story then explains that the topic still remains “confusing and controversial” because earlier research suggested mammography was lifesaving for some women.  

Jorgensen pointed me to a particular paper, in the January issue of The Breast, that gave an overview of various guidelines on breast screening and explained why recommendations differ. It mainly comes down to how the various experts interpret the science and how much weight they give to give different studies. But while the estimates vary on how many breast cancer deaths might be prevented by screening, it should be noted that no cancer screening has ever been shown to reduce overall mortality. Which is to say that women who are saved from breast cancer may be more likely to die earlier from something else.     

Many of the news stories mention some of the controversy and the different recommendations from organizations, but they don’t go further to examine the conflicts of interest and the amount of money that is currently being spent on mammography in the U.S.

To its credit, the NBC story noted the political aspects of mammography and the power it has over legislators, stating “Congress has even intervened, passing legislation overriding the USPSTF guidelines and requiring that insurance companies cover screening mammograms at no cost for most women who want them.

News coverage needs context to help women make these tough decisions

The crux of the issue is this: Whether to screen at the age of 40 is a personal decision for women who may make different decisions based on their personal values. Some may leap at any opportunity to receive early curative therapy — no matter how small the chance they will benefit or how great the potential harms — while many others will look at the same evidence and prefer not to know what a mammogram might find.

The choice is difficult, and journalists weighing in on the debate owe it to their readers to provide context that will help. This means not just passing along the recommendations from professional or advocacy groups, but exploring the cultural and financial influences that may have helped to shape those recommendations.

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Comments (13)

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Alexandra Payne

January 31, 2017 at 11:57 am

Thanks for speaking the truth, Alan!

Cornelia Baines

January 31, 2017 at 1:41 pm

Always have to hope evidence will change beliefs! A friend in NYC sent this to me Alan and it was such a pleasure to read your article. All the best.

Tom Monroe

February 1, 2017 at 5:34 pm

Ironically, while Cassels’ take is accurate he too still misses a huge part of the real picture about mammography.

The so-called independent mammogram scientists have been correctly focusing on the harm from overdiagnosis (and shown the lack of efficacy of the test), yet they have failed to recognize and acknowledge — just like the mammogram apologists — the true dangers of radiation exposure from mammograms. This group of “independent” people has primarily just reiterated — along with the mammogram proponents — the various falsehoods and dogmas about the radiation risk from mammography/x-rays, such that it is a negligible risk, that the radiation exposure has only local effects, etc (much of the real genuine evidence about the radiation dangers is referenced and discussed in the book “The Mammogram Myth” by Rolf Hefti), corporate medicine has been propagating now for about a century.

Therefore, the real question is how long will it take for THAT truth (meaning the whole truth) to finally enter the perception of authentic unbiased independent scientific minds and the public at large (sort of like the real facts on overdiagnosis from mammography have finally caught on among a larger number of people)? My guess is… at least many decades out.

Charles Carter

February 5, 2017 at 2:44 pm

Excellent article. And despite some shortcomings, kudos to the media outlets mentioned for reporting on the issue.
I’m inclined to believe mammograms of little value, certainly in women under 50.
You’re noting lack of all-cause mortality for any screening got me thinking though; especially in light of another recent widely (mis-) reported study on cervical cancer. Pap smears have tremendously reduced cervical cancer deaths since their introduction 60-70 years ago and have many characteristics of an ideal screening test. So I’ve an opinion that they are immensely valuable and save lives without the data for all-cause mortality. So far no other screening comes close in comparison. But I’m reminded that there are many pieces to the puzzle.

Sandra Gines

February 6, 2017 at 9:54 am

Thank you for the thoughtful treatment of the controversy over mammography guidelines in the US. As a breast cancer advocacy organization, we have sometimes been a lone voice in our statewide community in emphasizing the science behind the various recommendations. This is an issue that can become very emotional. However, in working with our sister organizations, we have come to emphasize the need for a conversation with one’s primary physician rather than a specific age at which to start mammography. We believe woman need to understand their individual risk in choosing when to start screening. Your article would be strengthened by noting that the age recommendations are usually for women of average risk, that is, women whose family histories and lifestyles do not have added risk factors for breast cancer. We believe women need to have discussions with their physicians about their risk level, and that these discussions will lead to the right recommendation for what age to start screening. Regardless of age, we believe that women whose doctors recommend screening should be able to receive this, covered by insurance.

Patricia Battaglia

February 6, 2017 at 3:37 pm

It’s an interesting and enlightening approach this issue to differentiate between those who stand to gain financially through screening mammography from those who have no vested interest in the process. This is a thoughtful, insightful analysis that adds additional perspective to the discussion.

John Galbraith Simmons

February 6, 2017 at 5:40 pm

Appreciate this article. But I’d like to suggest that the focus on media messages to women and to the public should also contend with how issues around mammography affect physicians, including oncologists. They have been struggling with this issue and also deal with media messages aimed at both them and the public. How are they doing?

Mark Ebell MD, MS

February 6, 2017 at 7:17 pm

I generally am sympathetic to your article (I am a former USPSTF member, full disclosure). But there actually has been a cancer found to reduce all cause mortality: lung cancer screening in the NLST. Also, because of competing causes of mortality, you need VERY large studies (on the order of 500,000 participants) to prove ACM reduction. Simple way to think about it is proving 2% vs 1.5% mortality reduction is a 25% RRR, whereas proving 20% vs 20.5% ACM reduction is much harder, as relative risk reduction is only 2.5%. Thanks for the great article!

Carolyn Thomas

February 7, 2017 at 8:17 am

Hello Alan,

Those who continue to push for screening, early screening and more screening for breast cancer already know that women have been convinced that such screening saves lives. It’s hard to unring that bell. When challenged with clear data like you present here, proponents point to the high-drama example of the deadly cancer discovered only because a woman was lucky enough to go for a mammogram. Who wouldn’t want to catch a deadly cancer early enough to save her life? Everybody nods in agreement and signs the donation cheques to provide more free screenings for poor women.

But there’s another side of this reality I rarely hear about. I am one of the women whose small calcified breast mass (non-palpable) was “caught” on a mammogram, an event that resulted in what doctors call quadrant resection surgery to remove that mass plus surrounding breast tissue. Good news! The mass turned out to be benign and non-cancerous.

After going through utter hell for the weeks around those terrifying test results, doctors’ appointments and ultimate hospitalization believing that I had breast cancer, I was supposed to just feel relieved and grateful to the brilliant surgeon about the disfiguring surgery I had just gone through.

How many other women like me have undergone unnecessary invasive procedures like mine based on the results of a mammogram that likely shouldn’t have been done in the first place?

Manuel Medina MD

February 12, 2017 at 8:12 am

As a radiologist who interprets mammograms on a daily basis its hard to justify delaying screening when in a week you detect findings that came out positive in two early forty patients without any family history or risk factors. The lives of these patients and their families will be changed forever. And they have a chance for survival that a delay in detection would have erased. When you talk to these patients, see their reactions, sudden fear and resolve, you understand that they’re not just statistics and numbers. I’m convinced that limiting screening would result in unnecessary deaths and suffering for many women. At least they deserve the opportunity. Thanks.

    Kevin Lomangino

    February 12, 2017 at 6:40 pm

    Dr. Medina,

    While I can’t comment on the details of these specific patients you’re discussing, I think it’s important for our readers to understand that in general, the idea that “early detection saves lives” is not supported by the evidence when it comes to mammography. More and more, we are learning that many breast cancer diagnoses represent “overdiagnosis” — meaning that the cancer being detected would never have gone on to cause a problem. Yet, women diagnosed with such tumors are exposed to very real harms–possible surgery, chemotherapy, radiation, and living life as a “cancer patient.” The problem of overdiagnosis needs to be part of the discussion when it comes to mammography. Your statement that a delay in detection would have “erased” a woman’s chance for survival is also problematic. If the cancer was not destined to cause a problem, finding the cancer early does not benefit the women whose cancer is found and exposes her to potential harms. And, unfortunately, it’s also true that some cancers are so aggressive that current treatments are ineffective, no matter how early the cancer is found.

    It’s precisely because we don’t see women as statistics and numbers that we believe they should understand what the evidence shows with respect to mammography. It’s only when women are fully informed about the benefits and risks of mammography screening that they can make the best possible decision.

    Kevin Lomangino
    Managing Editor

      Terri Farrugia

      February 13, 2017 at 10:56 am

      This was such a timely read for me. Just last week I went to see my new doctor for a meet and greet. He let me know right off that he was not one to immediately go the medication route and that he favored preventative medicine. I was very happy to hear that and told him so. However, the first question he asked was ‘when was your last mammogram?’ I told him I hadn’t had one since my mid-forties and was told back then that my breasts were very fibrous and made a reading difficult. He said that over the age of fifty I should be having one every two years, as recommended by many (there is no history of any cancers on both sides of my family, though I realize that’s no guarantee of never getting it.) But, I am concerned about too much radiation in general. I had a very bad experience after having a nuclear cardiology stress test. First, there seemed to be some doubt on the part of one of the technicians as I overheard him ask someone: “are you sure it’s okay to mix thallium isotopes with (inaudible)?”
      I have no idea what a thallium isotope is, but I’ll never forget the question being asked as it made me uncomfortable. As it was, we were called out of the blue to come in on the upcoming weekend, because there had been a shortage of isotopes for some reason, but they were expecting a new delivery and needed to use up what little was left (This was in Hamilton, Ontario mid-June of 2009).
      Second, no one ever mentioned that a person must drink lots of water over the next 48 hours to help flush out the radiation. I only found out about that a couple of years later in a conversation with someone. Worst of all was the burns on both shins and an itchiness that was so deep that nothing would touch it for the 3 weeks it nearly drove me out of my mind. I couldn’t sleep and quickly became depressed and anxious. No test that involves radiation should ever be taken lightly and I don’t know if I ever want to take the chance again.