Breast Screening – The Truth…

I am against over-medicalisation in all its forms. So, apart from being very skeptical about preventative medicine in the area of heart disease, I also worry about other forms of preventative medicine. Breast cancer screening is one area where the balance between benefit and harm may well slip towards harm. Yet, it is presented as an absolute good.

One man who is very critical of breast cancer screening  is Professor Peter Gotzsche, who is the clinical director fo the Nordic Cochrane Collaboration Centre, and has written a book called ‘Mammography Screening. Truth, lies and controversy.’ He outlines exactly what has been going on in this are, and makes it very clear that there are significant problems. Primarily with overdiagnosis (there are other problems, but no time for everything in one blog).

Overdiagnosis means finding ‘lumps’ of other suspcious things on mammography ‘lumps’ that would never have caused any problem.  How big is this problem. Well,  detailed pathological studies done in Australia found that in women who had died of other thngs (not breast cancer) had the following pathologies, any of which could lead to a ‘diagnosis’ of breast cancer if found on a biopsy :

Hyperplasia 12.6%
Carcinoma in situe 13%
Focal secretory changes 24.1%
Perilobular hemangioma 11.2%
Radial scars
(precursor of infiltrating ductal cancer)

In other words, a very high percentage of women have ‘cancerous’ lesions in their breasts. Yet, around 4% of women die of breast cancer.  In the words of the authors of this study…

‘….in any case, the high frequency of ductal hyperplasia and CIS (carcinoma in situ) 25.6% suggests that only a small proportion of these must ever progress to invasive carcinoma.’

If only a small proportion of ‘cancerous’ lesion actually progress to invasive carcinoma, then the majority of those found would never cause any harm to the woman. Thus overdiagnosis must be a very major problem indeed. Ironically, the more detailed an accurate screening beomces, the more overdiagnosis will occur.

Anyway, I was unsurprised to see the recent headline:

‘Breast cancer screening does ‘more good than harm’

‘Breast cancer screening saves the lives of two women for every one patient who receives unnecessary treatment, according to a major European review. There has been a fierce debate about the use of screening, and policy is being reviewed in England.

The latest study, published in the Journal of Medical Screening, said at least seven lives were saved for every 1,000 women screened. Health charities say the findings will provide further clarity for women. Tens of thousands of women die from breast cancer across Europe each year. The effectiveness of screening programmes across the continent was evaluated in a series of studies.

It concluded that for every 1,000 women screened, between seven and nine lives were saved and four cases were over-diagnosed.. Mammograms spot dangerous tumours, increasing the chances of survival, but also detect lumps that are essentially harmless, exposing some women to undue anxiety and surgery.

Screening doesn’t just save lives today or tomorrow, it saves lives 10-20 years down the line” Prof Stephen Duffy Queen Mary, University of London.’

I know that there is no possible way that anyone can know that for every seven and nine lives ‘saved’ four cases were overdiagnosed. This is scientific nonsense. The reality is that more cases must have been overdiagnosed than future invasive cancers diagnosed.

I have asked someone to forward me the full studies on which this BBC story was based.  I have only one part of it so far, and it is a part that worries me greatly, for it makes the following statement.

‘What these papers tell us is that the time has come to move away from relying solely on the older randomized trials of mammographic screening for the evidence-base, and to use data regularly collected and monitored from service screening programmes, with proper statistical analyses in addition to the results from the randomized trials. The authors of these articles set a precedent for how this could be done effectively.’

The time has come to move away from relying on randomized trials!

Once you move away from randomized trials you are no longer doing science. You are doing dogma. At which point the truth can never, ever, be obtained. When someone tells me we should use data regularly collected and monitored from service screening programmes with ‘proper’ statistical analysis – I know that THE TRUTH is being buried.

So long science.


21 thoughts on “Breast Screening – The Truth…

  1. Stella Topaz

    I agree that screening must not be promoted as ‘an absolute good’, and likewise ‘absolute bad’ is not helpful either! I want to know what may happen if I have a mammogram (including unintended outcomes) as well as what may happen if I don’t. I also want to know that information isn’t packaged to try to increase my compliance, rather than to increase my informed decision making. I want facts based on sound research and I want information to be free of coercion, blame or shame (eg: if I decline screening). Thanks for posting on this. It makes me more alert to the decision involved, and encourages me to be active in making an informed one.

    1. Dr. Malcolm Kendrick Post author

      I would advise reading Peter Gotzsche’s book. Mammography Screening ‘Truth Lies and Controversies.’ Although if you do no have a scientific background you may find it a bit tough going. I do not know if anyone can answer your questions fully, but you will end up with a better understanding of how the statistics work – or do not work.

    2. MEC

      Stella – Does not have to be a ‘mammogram’ screening per se. Can be an excellent ‘screening’ by *ultrasound – got to be a good diagnostic machine with an expert technician. Can *also be by *thermography. IF anything there, should show up, and IF summat does show up then, at that point, can go for the X-Ray.
      Do not permit yourself to be stuffed into a corner by some overzealous medic. Your body. *Your say.
      (No. I refused mamogrammes. No way).

  2. Odette Hélie

    I read part of Mr Gotzsche’s book (not an easy reading even if you have a scientific background). Overdiagnosis is not a minor collateral problem when talking about cancer : being treated for cancer and living with the fear of its resurgence is detrimental to mental and physical heath. I also learned (it was a surprise for me) that the radiation dose we get each time we submit to mammography is far from insignificant. Another variable, is the dependability of the results ( I am not talking about overdiagnosis, consequence of the powerful machines !) even if the radiologist is competent (an assumption that has been put to test by many recent scandals in Canada and Quebec). We learned recently that, in Quebec, we have many millionnaire radiologists, a medical specialty far less demanding than others. Also, it seems that, even after many years of systematic mammography in certain countries, the number of women who come to a physisican’s office with an advanced breast cancer has only slighty decreased. My conclusion is that if I get a really “bad” breast cancer, my chance of surviving are not really boosted by systematic mammmography (anyway, a fast growing cancer is often caught between mammographies) and if my cancer is of a less malignant type, again chances are my life will be spared, mammography or not !
    For all these reasons, I am considering getting out of the provincial program here (Quebec, Canada).
    Having followed the cholesterol debate for many years, I should not be surprised to see how brutal and unscupulous the scientists can be when their career and/or pocket is threatened…by science but I still find it sad, sad, sad. As a taxpayer, I wish the money devoted to public health would be more wisely spent ! So much to do, so few ressources !

    1. Dr. Malcolm Kendrick Post author

      Odette, I think you have good judgement. I find the entire area of disease screening to be almost the opposite of good science. Prevention is better than cure is a simple, easy to understand concept. But human biology and physiology is far from simple, and does not respond to simple ideas in the ways that we might expect.

  3. labrat

    They peddle fear. Women fear breast cancer like nothing else thanks to pink ribbons, much more than they fear any harm that might be done to them in the quest to prevent death from this disease or it’s treatment. Ask most women how they would feel if they found out they had a mastectomy for a lesion that never would have developed into cancer and they’ll tell you they’d rather be safe (and mutilated) than sorry. No rational argument will disuade them of that beleif.

    I’m with you on disease screening. The biggest con of all is the idea that it will save health care systems money. I’ve always had the thought that if I ever won the lottery I’d research and write a book about that scam. Remind me to buy a ticket…..

  4. tedhutchinson

    The perils of overdiagnosis
    Overdiagnosis as a consequence of PSA screening for prostate cancer is a major hazard of modern medicine, claims Margaret McCartney. Jon Rees, GP with a special interest in men’s health, and urologist Roger Kirby respond with their perspectives on this dilemma.

    Readers of this article may also be interested in this article about overdiagnosis in Prostate cancer. It seems to me if we know that IGF1 is playing a role in cancer initiation and progression (either breast or prostate) it’s simply common sense to reduce the dietary factors that increase insulin and IGF1.

    I don’t see that getting a PSA test to prove the numbers are rising should be necessary to scare people to eat more sensibly or raise their Vitamin D 25(OH)D to the natural level for human DNA.
    Vitamin D in the prostate

  5. Elizabeth EB

    I couldn’t agree with your comments more, it’s nice to hear a doctor making sense on this subject, rather than chastising women who “avoid” screening, naughty girls!
    It must be something to do with Scottish doctors, I’m a fan of your amazing Dr Margaret McCartney.
    I’ve read the book and recently heard Peter Gotzsche speak at the Evidence Live Conference in Oxford, his speech was compelling and worrying. (your Dr McCartney also, spoke very well) His points…about 50% of screen detected cancers are over-diagnosed, breast screening does not save breasts, you reduce the risk of a breast cancer diagnosis by one-third if you DON’T have breast screening…and any benefit of screening is almost certainly taken away by women who die as a result of lung cancer and heart attacks after radiotherapy and chemo. (Professor Michael Baum’s research in the BMJ, 2013)
    Also, Denmark has only been screening women in one area and so have the perfect control group…screening has not reduced mortality from breast cancer.

    Shockingly, women have been TOLD to screen for decades with no real or balanced information, we’re counted like sheep to achieve a govt-set target. I got to the truth early with cervical screening and so knew I should have a hard look at breast screening as well, (when I reached 50) I’m so pleased I did…once again, no respect for informed consent, misinformation, scare tactics, fudged statistics, vested and political interests. I’ll never understand how this has been acceptable for so long in women’s cancer screening.

    I do not have breast screening and have never participated in our cervical screening program. The latter program is hailed as the greatest success story in history, but no one mentions our shocking over-treatment rates…the lifetime risk of cervix cancer is 0.65%, it was always rare and in natural decline before screening started and there are NO randomized controlled trials for pap testing. The lifetime risk of referral for colposcopy/biopsy thanks to serious over-screening (almost all are false positives)…a whopping 77% (not that many women would have heard that figure)

    How can this be justified? Women here are still told they “must” or “should” have 26 pap tests, very bad medical advice. We do everything to maximize risk for no additional benefit, we screen far too early, too often and for too long. Since the 1960s the Finns have had a 6-7 pap test program, 5 yearly from 30 to 60, and they have the lowest rates of cc in the world and refer far fewer women for biopsies etc….we “treat” more than 10 times the number of women than a country like Finland. So this is not new evidence.

    The Dutch have the same 6-7 pap test program, but the Health Council of the Netherlands have recommended scrapping population pap testing and introducing 5 hrHPV primary triage tests offered at 30,35,40,50 and 60 and ONLY the roughly 5% who are HPV+ and at risk will be offered a 5 yearly pap test. (until they clear the virus) Most women are not even at risk…and are simply exposed to risk with pap testing. Those HPV- and no longer sexually active or confidently monogamous might choose to stop all further testing. The Dutch are already using a long overdue HPV self-testing device, the Delphi Screener. (also, available in Singapore; Australian women can order it from Delphi Bioscience in Singapore, I imagine UK women could order it from the Netherlands) This program will save more lives and spare huge numbers of women from a lifetime of unnecessary pap testing with the high risk of over-treatment. (which can damage the cervix and lead to premature babies, c-sections, miscarriages etc)

    The greatest threats to our health today IMO, are the screening programs that are aggressively pushed at women with no respect for informed consent or proper ethical standards. It seems a double standard still exists in medicine…we see something totally different in prostate screening…men got real information very quickly and doctors were reminded to obtain informed consent. Doctors here receive undisclosed target payments for pap testing…rewarded for seriously over-screening their patients, risking their health and happiness and IMO, this also, shows a cavalier disregard for our bodily privacy.
    Awful excess has been protected here for decades and that’s likely to continue into the future. Thankfully, more women are getting to the facts and making informed decisions not to screen, to screen later and less often and stopping earlier or are seeking out HPV primary testing and self-testing while they’re overseas or online. It’s time to take matters into our own hands, sadly, we cannot rely on the information and advice provided by these programs and the medical profession.
    HPV Today, Edition 24, sets out the new Dutch program
    Delphi Bioscience can provide information on HPV self-testing

  6. GG

    For years and years I went along for screening whenever I was supposed to. I don’t now. I have opted out of screening. Screening causes a lot of anxiety that some of us prefer not to experience again and again. Having had a number of breast lumps that each turned out to be a cyst I know what it is like to be waiting and wondering. I did not want mammograms and would make an appointment just for ultrasound as this showed up cysts best but a lot of pressure is put on patients to have mammograms even when you say you don’t want them. I was pressured into having mammograms and hey they acted surprised when I told them it was very painful at the time and I was left in a lot of pain for some time afterwards. Could it be because in my breast that they were squeezing to hell between two perspex plates was a large cyst (the word torture comes to mind). How can medical staff be so clueless and lacking in compassion regarding how painful these experiences can be? I lost count of the number of times I was offered surgery to cut out a cyst and if I had had them all cut out I would not have a breast left at all. I was even told that it was better to have surgery because there was a risk of infection each time I had a cyst aspirated. I would have thought that attacking my breast time and time again with a scalpel would have had an even higher risk.

    Too much pressure is put on people to have screening without explaining that they have a choice, that they are entitled to be properly informed of what the risks are and what the real benefits (if any) are. People who do not have screening should not be viewed as naughty children because they don’t want to play the screening game.

  7. Joan

    I recently found this blog and wanted to comment on this. For too many reasons to list here, about 8 years ago I decided to opt out of breast cancer screening. Am in the U.S. and every year I get a letter from my insurance company telling me “to immediately schedule a mammogram.” A local publication described women who didn’t have a mammogram EVERY year from age 40 as having a mental illness and being basically a coward really. If I go to the doctor for something completely unrelated, I get harassed for not keeping up with screening tests. I resent this. I have made an informed choice, so why am I labeled non-compliant, difficult, neurotic, etc. My fellow women can have half a dozen mammograms a year for all I care, just don’t keep berating me for MY choice. I also came to the decision I made long before reading various books which only strengthened my resolve not to participate in the screening religion. I definitely would not ignore symptoms, but choose not to go looking for trouble.

    1. Dr. Malcolm Kendrick Post author

      Well done. However, in the Brave New World of the future I imagine legislation will be passed to force all ‘non-attenders’ to have compulsory mammograms. [You read it here first]. The process will start by removing you from your health insurance scheme, or increasing payments.

  8. Lucy

    I wonder about Colonscopy too. I have heard from different people that they had persistent bowel problems after Colonscopy. One person I know got a hospital infection and nearly died after this procedure. I began to be very skeptical on this when doctor Oz said that Colonscopy “saved” him from cancer. They found a little something and now he has to go in more often for checking. How do we know that it was ever going to be a problem? Is going in the colon so often a good thing? The one woman I know that really is dying of bowel cancer, she had the Colonoscopy and it was clear. I guess they missed something, or it grew very quickly. What if the test actually injures the colon and spreads things around faster? hmmmm

  9. Kay

    I like my doctor. Some time back, he asked, “Ever have a mammogram?” And I replied, “No, and I won’t.” End of discussion. I’ve had a nurse in another office insist that I get a mammogram, and I had an awful time getting her off my back.

  10. Kay

    It’s interesting that there are perhaps hundreds of reasons a person might die, but nearly all the promotional effort is devoted to a half-dozen easily identifiable things that can make huge amounts of money.

    I would suggest that if we REALLY wanted to save lives, we’d skip all screenings and such, and go back to going to doctors for things like accidents and infections, and a few other things of proven medical benefit. Save the mammograms and other tests to diagnose, rule out, or manage actual disease. Forget about treating “risk factors” indefinitely with toxic drugs.

  11. Kay

    From time to time, I see mention of the Warburg effect, often together with suggestions that carbohydrate restriction might be useful in the prevention or treatment of cancer. Paul Davies’s video, posted by Stephen (thank you, Stephen!) on “A Swiss Investment Bank,” was the most recent thing I’ve read that mentioned the Warburg effect..

    I googled carbohydrate restriction and cancer, and one of the things I found was this:


    Check out the “sugar myths” listed here by these venerable organizations:

    National Cancer Institute

    Mayo Clinic

    Cancer Research UK


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