Breast cancer: study claiming that screening women in their 40s saves lives “found the opposite,” say critics
BMJ 2020; 370 doi: https://doi.org/10.1136/bmj.m3191 (Published 13 August 2020) Cite this as: BMJ 2020;370:m3191
All rapid responses
Rapid responses are electronic comments to the editor. They enable our users to debate issues raised in articles published on bmj.com. A rapid response is first posted online. If you need the URL (web address) of an individual response, simply click on the response headline and copy the URL from the browser window. A proportion of responses will, after editing, be published online and in the print journal as letters, which are indexed in PubMed. Rapid responses are not indexed in PubMed and they are not journal articles. The BMJ reserves the right to remove responses which are being wilfully misrepresented as published articles or when it is brought to our attention that a response spreads misinformation.
From March 2022, the word limit for rapid responses will be 600 words not including references and author details. We will no longer post responses that exceed this limit.
The word limit for letters selected from posted responses remains 300 words.
Dear Editor,
There are only two meaningful outcome measures in the practice of medicine as far as our patients are concerned; length of life (LoL) and quality of life (QOL). All other outcome measures need to be considered surrogate. This trial claims that screening woman under the age of 50 for breast cancer, will save lives without having a detrimental impact on QoL. Starting with the first claim let us look at the raw numbers without any modelling or “mathemagic”, and here I acknowledge the help of Dr Vinay Prasad. The percent of deaths from breast cancer in the intervention and control arms were, 0.39 v 0.44, whilst deaths from all causes were, 6.5 v 6.5. Little evidence for screening as a “life saver”. As there was no formal assessment of QoL then we have to make the assumption that over-diagnosis or false positive results might impact on the woman’s psychological wellbeing to which can be added the toxicity of any surgery, radiotherapy or systemic therapy as the consequence of over-diagnosis. From the data available the best estimates I can come up with are 18% for false positive cases and 17% for over-diagnosis during the intervention phase, a total of 35%. I derive the percentage for over-diagnosis from the numbers in the figure for incidence of cancers during the first five years of the intervention. That observation is supported by the relative risk for the diagnosis of DCIS during the intervention period, of 2.27. Screen detected DCIS is notorious for its multi-centricity and increase in mastectomy rates. [1] Sadly, a well-designed and very expensive trial with such mature follow up fails to demonstrate improvements in LoL or QoL. Had the authors accepted that their hypothesis had been refuted they would have been fêted, but in their determination to reinterpret the result in a favourable light, they leave behind the festering sore of ideological intractability.
[1] Jørgensen, Karsten Juhl and Gøtzsche Peter C. “Overdiagnosis in Publicly Organised
Mammography Screening Programmes: Systematic Review of Incidence Trends.” British Medical Journal 339 (2009): b2587.
Competing interests: No competing interests
Dear Editor,
Recruitment of the 160,921 women in this study took place from 1990 to 1997. We learn that `women in the intervention group were unaware of the study`. [1] In other words, they were denied their right to consider whether they wished to participate in the study. Screening by mammography is not without potential for harm: properly informed consent should have been sought from these asymptomatic citizens. [2] The fundamental principle of the Declaration of Helsinki, of respect for the individual and the right to make informed decisions, was ignored.
In July 1995, the House of Commons Health Committee published their Minutes of Evidence and Appendices in their Third Report, on Breast Cancer Services. [3] In the hearing on 30th March 1995, as a witness, I was asked by Alice Mahon, MP, “Mrs. Thornton, why do you think that the NHS Breast Screening Programme is, in your words “a costly trawl of an asymptomatic public group…creating huge costly psychological and physical morbidity”? Part of my answer was that it was because it “focuses on the women who benefit, in other words, the one life that is saved, and it overlooks the hundreds of women that go through the process and in some cases suffer psychological harm for that one. It is unbalanced and disproportionate and should be reviewed, in my opinion, at the moment.” Alice Mahon`s final question to me was “So you want a review then?” to which I replied “I do want a review.” I was not alone in wanting that!
After much clamour and controversy, an Independent Review took place in 2012. Much had happened in the years before its report was published in 2013, [4] and has thereafter. Treatments had improved enormously; women were presenting at an earlier stage in the disease; more evidence and information had become available and accessible to citizens. The magnitude of the harms inflicted on these unsuspecting and unaware women had also been quantified. [5] But reviews and sound evidence about harms and overdiagnosis have had little impact on all those who still talk in terms of `saving lives`, who disregard the collateral damage of the numerous harms suffered by hitherto asymptomatic citizens recruited to a study, some without their consent. They seem unable to see the wasteful disproportionateness of their stance at a time when currently, in the UK, for example, 1.85 million people are waiting for treatments put on hold in this time of pandemic. Only Covid-19 seems to have had the power to put a stop to breast screening when evidence, reason and clamours for distributive justice have not.
Meanwhile, the sick and ill suffer and wait, while statistics are presented that demonstrate the failure of devotees to get a grasp of the folly and injustice of attempting to increase the numbers of citizens who will be indisputably be harmed by widening the age range, with minimal or no benefit.
[1] Duffy S, Vulkan D, Cuckle H, et al. Effect of mammographic screening from age 40 years on breast cancer mortality (UK Age trial): final results of a randomised, controlled trial. Lancet Oncol2020. doi:10.1016/S1470-2045(20)30398-3. https://www.thelancet.com/journals/lanonc/article/PIIS1470-2045(20)30398-3/fulltext.
[2] Declaration of Helsinki https://en.wikipedia.org/wiki/Declaration_of_Helsinki
[3] Health Committee Third Report Breast Cancer Services Volume II Minutes of Evidence and Appendices. London HMSO 6th July 1995.
Hazel Thornton. Written evidence, pages 106-114: Page 111: Progress of NHS Breast Screening Programme.
Hazel Thornton. Oral evidence. Pages 123-124.
[4] Marmot G, Altman DG, Cameron DA, Dewar JA, Thompson SG, Wilcox M The Independent UK Panel on Breast Cancer Screening (2013) The benefits and harms of breast cancer screening: an independent review. Br J Cancer 108 (11): 2205–2240.
[5] Cochrane Review: Gøtzsche PC, Jørgensen K Screening for Breast cancer with mammography. June 2013
https://nordic.cochrane.org/screening-breast-cancer-mammography
https://www.cochrane.org/CD001877/BREASTCA_screening-for-breast-cancer-w...
Competing interests: No competing interests
Re: Breast cancer: study claiming that screening women in their 40s saves lives “found the opposite,” say critics
Dear Editor
Duffy et al state "Overall, there was no significant reduction in breast cancer mortality in the intervention group compared with the control group, with 209 deaths in the intervention group versus 474 deaths in the control group by the end of follow-up (0·88 [0·74–1·03]; p=0·13)".
So I am puzzled as to why their graph (Fig 2A) of breast cancer mortality during the follow up does not show the control and intervention groups converging, rather than the early advantage of the intervention group being maintained.
Competing interests: No competing interests