Women need better information about routine mammography
BMJ 2003; 327 doi: https://doi.org/10.1136/bmj.327.7406.101 (Published 10 July 2003) Cite this as: BMJ 2003;327:101
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Thank you so much for your article. As a woman who has put through
an ordeal by the "breast care" industry, I wish someone had gone over the
risks and benefits of breast cancer screening. What I learned is that
patients are not allowed to ask questions and try to do their own cost
benefit analysis. If they do, they get shunned. I was told I was
meanspirited in the same breath that I was told I had breast cancer. I
was told to have a partial mastectomy to comfort my doctor.
I was told
that it was "best." Ultimately the conclusion was that I had
fibrocystic breasts. After a year and 1/2 of sleepless nights and anxiety,
thousands of dollars and lost time from work, the last breast surgeon I
consulted with could not even look me in the eyes. The best she could do
was to tell me to reduce my caffeine intack. The medical industry lost a
whole lot of credibility and trust in my eyes.
I will never go for screening again for breast cancer or any disease.
Competing interests:
None declared
Competing interests: No competing interests
Dear editor,
we would like to raise issues around informed decision making by women on
screening mammography. We absolutely agree with supporting the autonomy of
women/patients. We would like to take into consideration that decisions of
women are not made in empty space but in a social context. The decisions
are framed by class and gender specific acceptance of prevention in
society. Women apply these preventive principles to themselves according
to believed positive health behaviour and not by the latest scientific
evidence. Therefore, we think it is unethical not to consider these
aspects of decision making related to screening mammography.
We want to point out that there are inconsistencies in information
gathering and transmission in screening mammography. Intervention aiming
at a healthy population presupposes estimating scientifically, potential
benefits and harms of the methods applied. The systematic review of Olsen
& Goetzsche (2001) shows that the benefit of screening mammography is
not evident, particularly not for all age groups of women. In their
review, the authors found no evidence in favour of screening mammography
programmes. To the contrary, mammography leads to more biopsies on women.
As a consequence, only very few important organisations in the preventive
field changed their guidelines (Humphrey et al., 2002). Why is it so?
Information on changes in breast density under hormone replacement therapy
relevant in this age group is mostly missing in guidelines (Kavanagh et
al., 2000). Why is it so?
If evidence was the only criterion, women under 40 should not be eligible
to join mammography screening programmes. In Austria however, in general,
patient information recommends baseline mammography (Rásky et al., in
press). How could this happen?
Breast cancer is a cancer of ageing. Is it sensible generally to stop
screening mammography at 69 years of age when this measure is considered
scientifically proven? And if there are doubts, why does the scientific
community not aim at initiating randomised trials evaluating the benefit
of screening mammography for older women?
In general, research information provided to the general public, at least
in Austria, does not present all aspects of mammography, in particular,
presenting benefits outweigh the presentation of harm. This is true for
information given in scientific publications, newspapers, and leaflets
(Slaytor et al., 1998).
Thornton et al. (2003) referring to the publication of Tabar et al. (2003)
and Otto et al. (2003), present a 44% mortality reduction in the screening
group without presenting exact numbers for the estimates of the group not
screened. The most positive presentation on the benefit of screening
mammography so far (obtained from a meta-analysis of randomised trials) is
a 30% reduction of mortality (Nyström et al., 1993). Both Tabar et al.
(2003) and Otto et al. (2003) can not clarify the causal effect of this
screening intervention on breast cancer mortality since they do not meet
the methodological standards required to this end. With the exception of
randomised trials, residual confounding as well as bias remain a
potentially serious problem, even after elaborate adjustments have been
made in the data analyses (Egger et al., 1998). The two cited studies may
have scientific merit but they are not providing evidence justifying the
implementation of screening mammography programmes. Why do media cite
these results more often than those of the systematic review of Olsen
& Goetzsche (2001)?
It took twenty years of practising screening mammography to start
discussing the autonomy of women. In the case of prostate cancer, men, in
contrast, from the very beginning of campaigns for screening have had
options, and a very accessible website offers pros and cons of the test
(www.cancerscreeing.nhs.uk/prostate/index.html). We get the impression
that screening for men is considered on a broader evidence base and with
more freedom of choice for the men concerned.
In the case of screening mammography with a population based preventive
strategy, we need more than 70% of women participating (Perry et al.,
2001). It is not yet understood in which way women decide whether to
accept screening mammography and how they apply all available information
(Curry et al. 1993; Schwartz et al. 2000; O´Sullivan et al.
2001). And what if too many women decide against mammography and thus
jeopardise the programme?
We consider it unethical to shift the responsibility of decision making
onto women without straightforwardly naming the scientific evidence for
benefit and harm of mammography. We fear that the autonomy of women might
be supported only at a point at which their physicians withdraw from their
responsibility. Is it really responsible to allow and demand
women´s informed decision making at a point at which not even
scientific medicine can make an evidence based recommendation?
Commenting on the picture illustrating the article by Thornton et al.
(2003): the picture does not follow the guideline of the General Medical
Council (1999) to allow patients sufficient time to reflect information
given by health providers. The woman shown is already half dressed and
prepared for the screening, a bad position in which to decline.
References
Curry SJ, Taplin SH, Anderman C, Barlow WE, McBride C. A randomised trial
of the impact of risk assessment and feedback on participation in
mammographic screening. Prev Med 1993; 22: 350-60.
Egger M, Schneider M, Davey Smith G. Spurious precision? Meta-analysis of
observational studies. BMJ 1998; 316: 140-44.
General Medical Council. Protecting patients, guiding doctors. Seeking
patients´ consent: the ethical considerations. London: GMC, 1999.
Humphrey LL, Helfand M, Chan BKS, Woolf SH. Breast Cancer Screening: A
summary of the evidence for the U.S. Preventive Task Force. Ann Intern Med
2002; 137: 347-60.
Kavanagh AM, Mitchell H, Giles GG. Hormone replacement therapy and
accuracy of mammographic screening. Lancet 2000; 355: 270-74.
Nystrom L, Rutqvist LE, Wall S, Lindgren A, Lindqvist M, Ryden S,
Andersson I, Bjurstam N, Fagerberg G, Frisell J, et al. Breast cancer
screening with mammography: overview of Swedish randomised trials. Lancet
1993; 341: 973-978.
Olsen O, Goetzsche PC. Screening for breast cancer with mammography
(Cochrane Review). In: The Cochrane Library, Issue 4, 2001. Oxford: Update
Software.
Sullivan I, Sutton S, Dixon S, Perry N (2001). False
positive results do not have a negative effect on reattandance for
subsequent breast screening. J Med Screen 8: 145-48.
Perry N, et al. European guidelines for quality assurance in mammography
screening. Luxembourg: European Commission, 2001
(http://www.euref.org/FOLDER_GUIDELINES_NW.PDF, last accessed 21th July,
2003).
Otto SJ, Fracheboud J, Looman CWN, Broeders MJM, Boer R, Hendriks
JHCL, Verbeek AML, de Koning HJ, and the National Evaluation Team for
Breast Cancer Screening. Lancet 2003; 361: 1411-17.
Rásky É, Groth S. Informationsmaterialien zum Mammographiescreening in
Österreich – Unterstützen sie die informierte Entscheidung von
Frauen? (Information materials on mammography screening in Austria
– do they help women with informed decision?). Soz Praventiv Med
(in press).
Schwartz LM, Woloshin S, Cox HC, Fischhoff B, Welch HG. US
women´s attitudes to false positive mammography results and
detection of ductal carcinoma in situ: cross sectional survey. BMJ 2000;
320: 1635-40.
Slaytor EK, Ward JE. How risk of breast cancer and benefits of screening
are communicated to women: analysis of 58 pamphlets. BMJ 1998; 317: 263-
64.
Tabar L, Yen M-F, Vitak B, Chen H-H T, Smith RA, Duffy SW. Mammography
service screening and mortality in breast cancer patients: 20-year follow-
up before and after introduction of screening. Lancet 2003; 361: 1405-10.
Thornton H, Edwards A, Baum M. Women need better information about routine
mammography. BMJ 2003; 327: 101-103.
Competing interests:
None declared
Competing interests: No competing interests
I accept that breast screening saves the occasional life. I accept
that screening is with us and here to stay and that it is vital part of
the health economy if not the wider economy.
This article was good in that it points out the lack of warning of
potential harm.
However any attempt to screen an entire population (albeit the cohort
50-64,)I would have thought, needs to have a test which is quick, easy,
relatively objective and probably done with minimal patient "consent". The
vast majority of women have probably neither the time not the inclination
to take on board the complexities of mammography screening as discussed in
Journals. They need and want to assume "having an X-ray prevents me dying
of cancer". Most probably do not want to, or to be more brutal probably
are unable to, take on any discussion beyond that level. That goes for
most screening we do including opportunistic BP measurement and PSA (to
avoid any accusations of sexism).
The fact that discussion about breast screening continue to rage
suggests that the benefits are marginal and need large studies to show
them. While we screen healthy women and subject most to an anxiety
provoking test which for most of them will prove to be a waste of time, we
increasingly live in a society which stresses everbody out considerably
increasing obvious disease. Screening by imposing a burden on society to
get to every patient to check them out increases that stress. In addition
screened diseases become somebody's fault. As GP I suspect I will be the
fall guy in the future for many screening failures.
Adding in the need for complex discussions with every patient on the
pros and cons is just a ridiculous idea which is doomed to fail and
consume vast amounts of NHS time in a task which must already be mind
numbingly tedious and where the benefits are marginal. Expecting staff to
robotically discuss the complex issues of screening with every patient
when even the academic world are unable to agree seems bizarre!
But then the whole screening business does provide a lot of jobs so
maybe the benefits do outweigh the costs
Screen breasts: yes but make it patient choice so that only patient
willing to enter these discussions come forward. Oh and of course make it
private so that the NHS illness service can get some more resources and
screening can rightly assume its place in the wider economy.
Competing interests:
None declared
Competing interests: No competing interests
Thornton, Edwards and Baum want women to be able to make "true
informed choices".
Do they mean:
"truly informed choices" (choices made after being informed – according to
a protocol - about the risks of benefits and harms, such that they are
assumed capable of choosing); or
"true, informed choices" (truthful - and valid – choices, after having
been informed of the risks); or
"truthfully informed choices" (choices made after being told the "truth"
about the risks)?
If the first, the adverb "truly", to modify "informed", would have
clarified the authors' meaning. If the second, a comma would have achieved
their purpose. If the third, "truthfully" might have been clearer than
"true".
In an area so fraught with misunderstanding, bedevilled by trying to
relate statistical information to one individual’s fate, the phrase "true
informed choices" can, like statistics, mean different things to different
people.
Further, the authors believe that "women need to fully understand
both the benefits and the potential harms". Undoubtedly, doctors’
obligation is to explain as best we can. Increasingly, in this
"information age", patients will come to understand more, but to
generalise that women "need" (as an absolute) "full" (as an absolute)
understanding is, with respect, unrealistic.
I suggest that the only patient possibly capable of such
understanding is a medically trained statistician who is not feeling
nauseated.
Competing interests:
None declared
Competing interests: No competing interests
Not only do women need to be offered better information (and access
to full information) about harms and benefits of routine mammography, the
public needs honest information about all screening tests and, indeed, all
tests, in order to give informed consent.
Few patients would realise that risks of ear syringing vary from
perforation (common) to aural polyps (rare), yet complications of this
procedure are the commonest cause of litigation against GPs.(1)
Men who request testing for prostate cancer and are told explicitly
about the advantages and disadvantages are then likely to change their
minds (cost effective information giving).
Women who refuse an invitation to breast screening and are offered
discussion on the issue by their GP (as well as those invited for cervical
smear taking) need to know the minus as well as the plus side of
acceptance. Good written information aids transparency and protects
against accusations of coercion.
Any payment linked to numbers of people screened creates a vested
interest in compliance.
The public no longer wants doctors to "manage uncertainty by
fibbing". (2) The government and the public want patients to have more
control over their own healthcare. Bland reassurance is no longer
acceptable; the public wants truth. Health services need to wake up and
catch up.
(1) Gillett D, Lewis N, Patel H, Wareing M.GP Clinical.16.06.03.
(2) Farrell L.GP Opinion.9.06.03.
Competing interests:
None declared
Competing interests: No competing interests
I read the paper by Thornton et al with interest and the reply by
Julietta Patnick. Both the National Health Service Breast Screening
Programme (NHSBSP) and cervical screening programme have made great
efforts to improve the understanding by women of the principles of
screening since Dr. Mary Anderson and I wrote a paper critical of the
information given, back in 1999. Unfortunately there is clearly someway to
go.
According to a recent report from the Cancer Research UK Psychosocial
Oncology Group at the University of Sussex patients remain confused. The
BBC, quoting from the report, states that: "They were also flummoxed by
terms used to describe screening procedures for breast and bowel cancer."
and "More than half of the study group either didn't know or showed
partial understanding of breast cancer screening techniques such as
mammography." (http://news.bbc.co.uk/1/hi/health/3071937.stm).
It is also disappointing that the leaflet to which Mrs. Patnick
refers (Breast Cancer: the facts) omits to mention the potential
consequences of being screened, namely invasive biopsy procedures or even
mastectomy, with their attendant morbidity. Whilst these eventualities may
only affect a minority of those being screened, they are surely worthy on
mention in a pamphlet to purporting to telling it how it is, especially
since most of these women are healthy before undertaking the screening
test.
Given the time and effort spent in ensuring that bereaved relatives
are given appropriate information prior to their next of kin undergoing a
post-mortem exam, surely it is time truly informed consent was given to
participants in screening programmes so they exactly what it is they are
signing up to.
1. Anderson CM. Nottingham J. Bridging the knowledge gap and
communicating uncertainties for informed consent in cervical cytology
screening; we need unbiased information and a culture change.
Cytopathology. 10(4):221-8, 1999 Aug.
Competing interests:
None declared
Competing interests: No competing interests
The paper by Thornton et al, BMJ 2003;327:101-3 reinforces the need
to take a population perspective to the measurement and communication of
risk. The Population Impact Number (PIN) is defied as “the number of those
in the whole population amongst whom one event will be prevented by the
intervention”1;2. I have calculated PIN from England and Wales mortality
data for 2001, assuming that mammography leads to an 24% and 18% relative
risk reduction of breast cancer mortality among women aged 50-59 and 40-49
years respectively, and that 70% of women attend for screening. A policy
of screening among a population of 164,773 women aged 50-59 years will
lead to one less death from breast cancer per year, the figure for women
aged 40-49 years being 470,312. This extends the number needed to screen
quoted by Thornton et al, and allows the health gain to the population
from a policy of mammography to be compared with the health gain from
alternative interventions. Whether the presentation of information in this
format will help individual women to make a choice about accepting an
invitation for screening remains to be tested.
References
1. Heller RF, Dobson AJ. Disease impact number and population impact
number: a population perspective to measures of risk and benefit. British
Medical Journal 2000;321:950-2.
2. Attia J, Page JH, Heller RF, Dobson AJ. Impact numbers in health
policy decisions. Journal of Epidemiology and Community Health 2002;56:600
-5.
Competing interests:
None declared
Competing interests: No competing interests
I recently declined a birthday present from the NHS – an invitation
to attend for my first routine mammogram, the appointment nicely timed for
my 51st birthday! As a doctor specialising in reproductive and sexual
health I was in the fortunate position to be able to make a realistic
assessment of my own risk factors, as advocated by Thornton et al (BMJ
12.7.03). This led me to the conclusion that for me the risks of
screening on this occasion outweighed the benefits, so I politely declined
the invitation. Thornton et al are correct in their assertion that all
women need to be able to make this choice, based on information they can
understand. The challenge is how to achieve this, but a commitment to
this ideal would be a good place to start.
Competing interests:
None declared
Competing interests: No competing interests
There is a great deal of evidence on how risk should be presented to
facilitate understanding. [1] Absolute risks should be given more
prominence than relative risks. The effects of the decision over the
individual's lifetime should be presented rather than the effects in the
next few years. The way information is framed also influences the
decisions people reach. Reductions in losses (e.g. "screening decreases
mortality from 6% to 4%") are more persuasive than increases in gains
(e.g. "screeniing increases survival from 94% to 96%").
Unless our aim is to manipulate the influence of framing should be
minimised by presenting risks of both gains (survival) and losses
(mortality). Individuals tend to find it easier to understand data
presented in the form of integers (3 in 10 people) rather than
probabilities (30% of people). Any attempt to present risk information to
women should make use of decision aids. [2]
Current breast cancer information leaflets do not contain information
on absolute reduction in mortality or absolute risk of further
investigation over the course of a screening career and do not use any
decision aids. [3] There are now published decision aids for breast cancer
screening that meet at least some of these requirements. [4] Hopefully
they will soon be found in future leaflets.
REFERENCES
1. Edwards A., Elwyn G., Mulley A. Explaining risks: turning
numerical data into meaningful pictures. British Medical Journal
2002;324:827-30.
2. O'Connor AM, Stacey D, Rovner D, Holmes-Rovner M, Tetroe J,
Llewellyn-Thomas H, Entwistle V, Rostom A, Fiset V, Barry M, Jones J.
Decision aids for people facing health treatment or screening decisions
(Cochrane Review). In: The Cochrane Library, Issue 2, 2002. Oxford: Update
Software.
3. Breast Screening - the facts. Published by Health Promotion
England in association with the NHS Cancer Screening Programmes, with
advice and support from the Cancer Research Campaign Primary Care
Education Research Group. Crown copyright, London 2001.
4. Marshall T. Adab P. Informed consent for breast screening: what
should we tell women? Journal of Medical Screening 2003; 10(1):22-26.
Competing interests:
None declared
Competing interests: No competing interests
Conflicts in health screening
In their article, Thornton et al. explore some of the many
uncertainties surrounding breast cancer screening, and allude to the fact
that much of the information provided to patients in the context of
screening mammography is biased towards increasing uptake, even without
women acquiring substantial understanding of the process.1 These are
indeed significant problems which interfere with patients’ ability to make
truly informed choices. However, despite being important confounders, the
argument in favour of informed choice in relation to screening should not
rest on any inherent uncertainty or bias.
The difficulty with screening is that, despite its prominence in
modern medicine, it resides distinctly outside the traditional patient-
doctor framework, and as such raises unique ethical concerns. Screening
programmes utilize familiar health-care resources to achieve end points
determined elsewhere, away from the individual patient. Yet these
programmes require the participation of those targeted, who themselves are
presumed healthy. Given this, conflicts will remain inevitable in
population-wide health programmes unless unanimity can be achieved; but
this is precluded by the evaluative nature of health, disease and illness.
And whilst agreement is possible on health as being valuable, it is less
so on its desirability or priority. Furthermore, screening cannot be
justified on grounds of its being either moral or universally rational to
pursue, nor on the grounds of its being collectively rational in the
pursuit of a generally agreed, and hence aggregated, good. Indeed the
legitimacy of the notion of ‘collective’ choice is open to question. Thus,
despite protestation that at least some screening programmes might be
beneficial, the notion itself necessarily risks conflict.2
Indeed, similar arguments could be made in relation to immunisation
and many other public health programmes, and the failure of professionals
and policy makers to appreciate this, risks alienating the increasingly
critical public. This calls for an inclusive debate aimed at defining the
conceptual framework for these programmes.
1- Thornton H, Edwards A, Baum M. Women need better information about
routine mammography. BMJ 2003; 327:101-3.
2- Habiba M. Health screening: a libertarian perspective. PhD thesis,
University of Wales, 2000.
Competing interests:
None declared
Competing interests: No competing interests