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SINCE federal government support of the national mammography program (Breastscreen) began in 1991, mortality from breast cancer in Australia has declined by 28%, but how much of this improvement can be attributed to screening and how much to improved adjuvant treatments?
Disentangling the contributions of screening and improved treatment to reduced mortality is challenging. However, the incidence of breast cancers (BCs) that are advanced at the time of diagnosis is one measure that could be useful. For screening to have an independent impact on mortality it must be able to reduce the incidence of advanced tumours, but recent evidence does not indicate that this is the case.
A recent study, which included 14 countries and regions with at least 7 years of mammography screening, has failed to find a reduction in the incidence of advanced cancer in countries with sustained use of screening.
It is now also clear that the improvements in BC mortality are not restricted to populations with screening. A paper in the BMJ, reported similar mortality reductions for breast cancer in countries with and without screening programs for the same period: Northern Ireland (screening) versus Ireland; the Netherlands (screening) versus Belgium; and Sweden (screening) versus Norway.
This follows reports in 2009 and 2010 of analyses of trends in breast cancer mortality that concluded that improvements in BC mortality could not be attributed to screening in Denmark, Norway and the UK.
In Australia, the 5-year survival rate improved from 71% to 83% between 1986 and 1995, before Breastscreen could have had an impact, and improvements in adjuvant chemotherapy and endocrine therapy received by Australian women during this period could explain most, if not all, of the observed decline in BC mortality.
The introduction of screening has been associated with a sustained increase in the incidence of invasive BC, most evident in Australia for women aged 60-69 years who have had the highest Breastscreen participation (almost 60%), but lowest mortality decline (19%). This raises the question of whether screening is responsible for overdiagnosis of BC.
Overdiagnosis refers to BC that would not have manifested clinically in a woman’s lifetime and therefore would not have been diagnosed in the absence of screening. In Australia, overdiagnosis from screening has been estimated at 30%-40%. Overdiagnosis would be even greater if ductal carcinoma in situ detected by screening was also taken into account.
The issue then becomes: what is the balance between lives saved and harm from overdiagnosis and unnecessary treatment? Estimates derived from randomised screening trials have produced a range of ratios between harms and benefits, with the possibility that the balance could be as unfavourable as 10 women overdiagnosed for every life saved.
Why are we saying this now when the message in the past has been to encourage women to be screened?
The original trials demonstrating the benefits of screening were carried out between 1960s and 1980s, when 5-year survival rates for women with BC was much poorer than it is today and adjuvant therapy was received by only a small minority of women. The remaining potential benefit of earlier diagnosis is now much less and, considering the issue of overdiagnosis, a simple message of unqualified benefit from screening is no longer appropriate.
So what should women be advised about screening mammography?
The harm of screening is not currently being explained in the UK screening program, leading to a call for a better balance in the information provided to women.
We consider that Australian women should also be given more information about the balance of benefits and harms of screening so that they are better equipped to make an informed choice.
Associate Professor Robin Bell is the deputy director of the Women’s Health Program, School of Public Health and Preventive Medicine, Monash University. Professor Robert Burton is from the School of Public Health and Preventive Medicine, Monash University.
Full reference details are available on request from editor@mjainsight.com.au
Posted 26 September 2011
I was delighted to see my wish came true yesterday when I picked up the newspaper. A huge thank you to Assoc Prof Bell for helping the women of Australia and taking a brave step many others were not prepared to take…
I was relieved to see Prof Olver from the Cancer Council supports the need for women to receive more information on the risks and benefits of breast screening including information on over-diagnosis. I hope other doctors also support Assoc Prof Bell – that will ensure this issue stays alive and something is actually done.
I thought the comments made by Breast Screen were very patronizing – if there is uncertainty about benefit and concerns about risk, you don’t hide it, you MUST tell women and let them make up their own minds.
I don’t for one second accept they were waiting for a consensus, they are concerned about reaching the target and feared this information might put some women off testing.
I’d urge all of our doctors to stop co-operating with these programs and put us first. The govt has no business getting between us and asking you to do their dirty work. If they can’t offer a test with full disclosure and respect for informed consent (no pressure, no scare campaigns, no biased and inadequate brochures, no target payments, etc) – it’s not a suitable population screening test.
The UK have now decided to do a major review of the risks and benefits of breast screening, thanks to the amazing and persistent pressure applied by Prof Michael Baum and others. It’s wonderful news for the women of the UK.
Hopefully, some of this news will reach Australian women or encourage some of our doctors to take some action to warn women and force Breast Screen to respect informed consent.
Many now believe the risks of breast screening exceed the benefits. We should not ignore the evidence and keep recommending women screen to achieve the govt-set target with no regard for their health and rights.
http://www.guardian.co.uk/society/2011/oct/26/breast-cancer-screening-re…
Also, read the letter from Dr Bewley that finally convinced the NHS to conduct an independent review.
http://www.bmj.com/content/343/bmj.d6843
Thank you for such a different view on breast screening, it was quite refreshing to read. Earlier this year I found a mass in my breast, it was tender and mobile quite large. I saw a doctor, had a biopsy and ultrasound – inconclusive. Reffered to a specialist – advised to repeat tests along with a mammogram. All along I was asking, why a 25y.o otherwise healthy female with dense breast tissue, with no family history must undergo a mammogram? This made me really angry – mammogram inconclusive, further ultrasound inconclusive. Radiologist made me feel guilty for not consenting to another core biopsy saying: “Don’t you want to know if you have cancer?” I am angry at the system and the thoughtless things that medical staff say. My mass went away after taking some chinese herbs and focusing on relaxation. Women don’t need to be fear driven, we just need to be well informed!
“I think it’s time we treated screening as we do prescribing medication or performing surgery i.e. use an evidence based practice, consider all the side effects, costs, etc and obtain proper informed consent.”
Scott, I hope more doctors start to think that way.
Our cervical screening program is a real concern as well – it over-screens and screens inappropriately which increases the risk of a false positive and biopsy/over-treatment for no additional benefit. Apart from risking our health, putting women through an invasive exam more than necessary, in my opinion, shows a lack of regard for our bodily privacy/autonomy.
Dr James Dickinson in “Time to change the Policy” back in 2002 contains a chart that compares the various programs around the world. The Finnish have the lowest rates of cervical cancer in the world and refer far fewer women (fewer false positives) – they offer 7 tests in total. An Australian woman will face 26 tests over her lifetime. (if not more)
http://www.mja.com.au/public/issues/176_11_030602/dic10690_fm.html
Annual and 2 yearly testing is over-screening – which means the lifetime risk of referral for colposcopy and usually some sort of biopsy in this country is a whopping 77%, for a rare cancer with a lifetime risk of just 0.65%…and cervical damage is now linked to premature babies and the need for c-sections. (and other issues)
We also continue to screen young women, even though the evidence has been clear for a long time now – screening does not change the tiny death rate in women under 30, but exposes them to risk/harm. The most false positives are produced by women under 25. (1 in 3 according to Dr Angela Raffle, UK screening expert)
Many countries exclude these women for their own protection. There have been calls to change our program for many years, but nothing happens – we continue to over-screen and worry and harm as many women as possible.
I saw some research in the “Lancet” recently that shows the pap test records of young women are being compared to HPV vaccination records – is this research holding up long overdue changes to our program? Has anyone obtained informed consent (or any sort of consent) from these young women to continue with pap testing purely to facilitate this research? (when testing can only mean harm for no benefit) Is it the case these programs are free to operate outside acceptable ethical standards and the law? They write up their own rules, anything goes!
It concerns me that other countries are challenging these programs, warning women and forcing changes to better protect the more than 99% who’ll never benefit from testing…while nothing is happening here.
Our doctors know what’s going on, but either don’t care, benefit financially from the excess or don’t feel they can challenge these programs.
In “Cervical cancer screening” in Australian Doctor, July 2006 by Assoc Prof Margaret Davy and Dr Shorne, it’s mentioned that, “no country has shown a reduction in the incidence of or the mortality from cervical cancer in women under 30, irrespective of cervical screening”.
Other countries also give women options to reduce risk…the Netherlands are looking at moving from 7 pap tests over a woman’s lifetime to 5 high risk HPV primary screening tests (and a self-test kit is available) At age 30 women will be offered the first hrHPV test – those negative can retest at age 35, 40, 50 and 60. This enables the small number “at risk” to be identified and lessens the negative impact of the program on other women. At age 40 only 5% of women are HPV positive.
Women who test negative and in a monogamous relationship or no longer sexually active might choose to stop testing altogether.
Yet Aussie women are still being offered a harmful and excessive program…and more than offered, many women feel pressured into this program.
What is going on in this country?
http://www.cancer.org.au/Newsmedia/Issues_in_the_media/HPVvaccine.htm
The World Health Organization guidelines on ethical screening were published in 1968:
1.The condition should be an important health problem.
2.There should be a treatment for the condition.
3.Facilities for diagnosis and treatment should be available.
4.There should be a latent stage of the disease.
5.There should be a test or examination for the condition.
6.The test should be acceptable to the population.
7.The natural history of the disease should be adequately understood.
8.There should be an agreed policy on whom to treat.
9.The total cost of finding a case should be economically balanced in relation to medical expenditure as a whole.
10.Case-finding should be a continuous process, not just a “once and for all” project
Our Breast Screening Program ticks all of these boxes, with the possible exception of “9”. There are potential harms – almost none life threatening.
Those wishing to offer another “evidence based” approach approach would have to be able to balance the benefits of waiting until breast cancer became symptomatic against the potential loss of survival by delay in diagnosis, or at the least a “non inferiority” of this approach.
Breast cancer mortality has decreased since the introduction of Breast screening – perhaps not cause and effect. We await proof that they are not cause and effect – in the meantime, I’ll back breast screening.
@Elizabeth – interesting comment. I have to agree with a lot of your points there. Given the lack of clear-cut evidence that these screening problems are making significant differences in mortality we should definitely recognize some of the adverse effects apart from the obvious “overdiagnosis” – I’ve obviously only ever experienced pap-smears from my perspective as a doctor but I can imagine that it can be a very unpleasant experience. Similarly a lot of women complain of pain from mammograms, not to mention the time and financial costs associated with these. I think it’s time we treated screening as we do prescribing medication or performing surgery i.e. use an evidence based practice, consider all the side effects, costs, etc and obtain proper informed consent.
Screening has this “saintly” aura and to question it is to risk accusations of heresy from the high priests of the screening industry. Congratulations to Robin Bell and Robert Burton for this article.
When the facts are examined screening does some good but considerable harm. The benefits are grossly overstated and the risks never discussed.
Time for the facts to see the light of day so that people can make informed decisions and not be railroaded.
If only this information were published in the “Age” or where more women could find it. I do see some respect for informed consent in breast screening (not much for cervical screening) in Australian medical journals, but very little anywhere else. Most women get very little unbiased information about screening. Last night we had Helen Zorbas from Breast Screen on the “news” urging women to have mammograms – we should be reassured and have confidence in screening after a Swedish study showed a 30% fall in deaths from breast cancer over the long term in screened women. Of course, she omitted to mention the more recent study that showed the fall in the death rate is about better treatments, and not screening. This is the selective use of facts and research that is typical in cervical and breast cancer screening. Yet not one doctor or anyone else steps forward and challenges these groups or warns women of critical omissions. It seems informed consent for women in screening is a joke.
Our programs are highly political and loaded with vested interests. It shocks me that unethical conduct is apparently acceptable if it’s directed at women. In my opinion, far more women are harmed than helped by these programs. Over-treatment is “massive” in cervical screening – all for a rare cancer that affects less than 1% of women and was in natural decline before testing started…the word “massive” is not mine (although I agree with its use), it came from Dr Alex Barrett in the ABC series, “The Health Report”.
I also know that few women are giving informed consent for screening and no one seems to care. I look to the Nordic Cochrane Institute and the UK for balanced information. The UK is fortunate to have lots of doctors keeping these programs accountable and fighting for informed consent. Prof Michael Baum, UK breast cancer surgeon, has called for breast screening to be scrapped and is suing the NHS for failing to obtain informed consent from women. If only we had a Prof Baum!
A double standard exists here – women can be told whatever is necessary to get them to screen and we’re counted like ignorant sheep to reach govt-set targets. Our GPs even receive target payments for pap testing, although most women are unaware of this potential conflict of interest. In sharp contrast, men were advised of risk with prostate screening and doctors were reminded to obtain informed consent.
This is not cancer screening, not even close. Cancer screening is an “offer” to a healthy population with full disclosure of risks and benefits and only carried out with informed consent.
I have rejected both cervical and breast cancer screening on the basis of information that is NOT released to women.
I’ve watched for decades the fear, worry, harm, embarrassment, pain and damage these programs cause to healthy women and all with NO informed consent.
These programs operate outside ethical standards and the law and any critics have been silenced. (we must have some!)
Dr Margaret McCartney, Scottish GP, published an article in the BMJ recently, “Doctors should not support unethical screening programs”. I’m hopeful more doctors will stand up and defend our right to informed consent, rather – their first duty is to their patients, not to these programs.
THe whole of screening needs a good hard look at – much of the Breastscreen explosion has been politically driven rather than due to a cost-benefit analysis. Whereas Breastscreen started as an adjunct to management it has become an self-serving entity spawning the breast physician and driving away referrals from general surgeons to so-called breast surgeons who aren’t above dabbling in much of general surgery.
I wonder how much of the so-called increase in cancer diagnosis is due to labelling DCIS as cancer when if fact 2/3 of these are non-progressive. It is increasingly evident to me that there is plenty of money in the health services – it’s just going into the wrong places, paperwork, QA, regulation, politics ….