Researchers give mammography another vote of no confidence

Mammography is a screening tool designed to diagnose breast cancer earlier than it other would be, which should lead to earlier, better and more effective treatment. Well, that’s the theory anyway. But as with the case with many things, theory does not always translate smoothly into practice. There has been for some years now growing doubts about the value of mammography. Two charges that have been made by some researchers is that mammography actually isn’t very effective at saving lives, and at the same times leads to more women being subjected to investigation and treatment for breast cancers that would never have been an issue if left alone.

And one more criticism has been that women have generally not been fully informed about the pros and cons of mammography. This means that most women have simply not been given the opportunity to make truly informed decisions about whether or not to have a mammogram. For more about the issues surrounding mammography, see here and here.

This week saw the publication of another study which sought to gauge the effectiveness of mammography. The study, published in the New England Journal of Medicine, assessed the outcomes of more than 40,000 women with breast cancer. Access to screening was associated with a 28 per cent reduction in risk of dying from breast cancer. This outcomes looks quite good on the face of it. However, breast cancer is one condition for which treatments have improved quite considerably in recent times. This means that at least some of the benefits associated with mammography may come from improvements in breast cancer care that have coincided with mammography screening.

This study found that in women who were not screened, mortality from breast cancer fell considerably too. It turns out that only about a third of the 28 per cent reduction in risk of death associated with mammography was down to mammography per se. In other words, this study found that mammography was associated with a reduced risk of death of breast cancer of about 10 per cent.

10 per cent might sound worthwhile, but how big the real benefits are depend on how likely women are to die from breast cancer. If, say, a woman’s risk of dying from breast cancer over a 10-year period is 10 per cent, then mammography (according to this study) would be expected to reduce this to 9 per cent (a 1 per cent reduction).

An accompanying editorial [2] puts the real figures into some perspective. If 2,500 women aged 50 were screened with mammography, only ONE will avoid dying of breast cancer. Now, many of these women (as many as 1000) will have to endure the potential stress of being told by their doctors that there’s something suspicious on their mammogram. And about 500 of these will go on to have a biopsy – an invasive procedure around which there is usually considerable anxiety. As a result of biopsy, it is estimated that between 5 and 15 women will be treated unnecessarily for a condition that was never going to bother them.

While mammography still has ardent support in some quarters, mounting evidence suggests it really is less beneficial and more hazardous than women have been led believe.

Out of curiosity I recently asked my 77-year-old mother (a retired doctor) if she’d ever had a mammogram. ‘No’ she replied, and in a way that said ‘why would I want to do that?’. Perhaps mothers do know best, sometimes.


1. Kalager M, et al. Effect of Screening Mammography on Breast-Cancer Mortality in Norway. N Engl J Med 2010; 363:1203-1210

2. Welch HG. Screening Mammography — A Long Run for a Short Slide? N Engl J Med 2010; 363:1276-1278

10 Responses to Researchers give mammography another vote of no confidence

  1. Margaret Wilde 24 September 2010 at 8:15 pm #

    I’ve always considered mammography screening to be largely a matter of NHS politics: a provision intended to make women feel their health was being safeguarded.

    As a general rule I am against screening, being ardently against avoidable ionising radiation, and I have never accepted an invitation to go for a mammogram.

  2. catherine 24 September 2010 at 11:20 pm #

    I too, have never been for a mammogram. My sister has and went through the anxiety of an ‘unidentifiable mass’, a biopsy and the prolonged waiting period over a weekend – the result was ‘nothing to be worried about’. I am an ardent follower of your blog and feel ever so relieved at reading your mother’s ‘no’, it is exactly how I feel. Thank you always, for your poignant blogs.

  3. Sally Seal 25 September 2010 at 8:11 pm #

    I live in France where for the over 50’s they screen every 1-2 years. For the last 3 years I have resisted the invitation to go for a mammogram, I am 53. I have come under pressure from female friends, 1 of whom, she says, screening saved her life. My husband has also been nagging me. I have followed the blog’s of Dr Briffa who has confirmed my doubt about the whole procedure. I cannot see that willingly submitting to a intense dose of radiation will help prevent cancer and this has made me decided that I will not have one. My mother who is 77 has never has and she is fine. My husband on reading this blog and others supplied by me has said he now will respect my decision and will no longer mention it.

    I have long held the thought that if men had to submit to some of the extremely invasive and sometimes painful tests that women do on a regular basis they would have come up with something better!

  4. Feona 26 September 2010 at 11:30 am #

    There’s something else about mammograms that you haven’t mentioned – it hurts! Doubt I’ll ever bother again.

  5. helen 26 September 2010 at 11:42 am #

    I have to agree with your Mum and both posters. I consider it a form of insanity to go looking for an constantly worrying about things like breast cancer. As I have never had a mammogram myself I can only go by what others have told me and I wonder how they can be sure that it isnt the proceedure that does damage in the long run. Also I believe that you get what you expect out of life so if you are putting yourself through a yearly and monthly exercise of “looking” for & worrying non stop about cancer then surely you will eventually find what you are looking for??

  6. LM 27 September 2010 at 12:23 am #

    Here in the US women are encouraged to go yearly starting at 40, and most I know do. I think though it depends as much on your personality type as medical history whether its worth it. I’m a worrier without a family history of any cancer. So for me this is most likely to just increase worry, and I’ve only been once while covered by insurance for 3 years.

    But I hear so many stories from friends of family members who had cancers caught early, that I can see that for others its worthwhile. At a societal level, it depends what else we want to pay for in its place. I suspect there are a lot better uses of the money, but when we’re used to getting them at 40, the suggestion we push it back leaves people screaming.

  7. Gail 27 September 2010 at 7:07 pm #

    I am 59 years of age and have had yearly mammograms since I was 25 on the advice of my doctor because my breasts are dense. For the past 3 years because of breast density I’ve had follow up ultra sounds done about a week after my initial mammogram. I’m seriously swaying toward NOT getting a yearly mammogram, enough is enough after 34 years, because of radiation, and looking into thermal imaging. I’m curious to know if any of you ladies out there have turned to thermal imaging and if so, your thoughts.

  8. cheryl 5 October 2010 at 8:03 pm #

    After reading Gail’s comment I am very glad to know there is someone who feels the same way I do I started yearly mammograms at age 40 I’m now 61 and I do not want to have another mammogram. I honestly believe they cause breast cancer. I too am considering themal imaging but it is hard to find a clinic in the US. There has to be a better way to deal with breast health than having them nuked for the rest of your life which I was told that’s how long you have to have them!

  9. LaTrisha 6 December 2010 at 8:33 pm #

    I have never had a mammogram! Radiation causes cancer. How can it possibly be a good idea to bombard your breasts with high doses of radiation every year?! Not only that, but the effects of radiation are cumulative. I would be perfectly willing to undergo thermography, however. If only it were available in my area!


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