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Rapid Responses: Rapid Responses published:
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Timing of publication of AGE trial results
- Sue M Moss, Howard Cuckle (5 March 2004)
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`AGE` Trial results: effect on lives or effect on death?
- Hazel Thornton (8 March 2004)
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Sue M Moss, Associate Director, Cancer Screening Evaluation Unit Institute of Cancer Research, Sutton, SM2 5NG, Howard Cuckle
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Editor – Hazel Thornton questions why the results of the AGE trial of breast screening by mammography starting at age 40 have not yet been published [1]. She is correct to state that the trial began in 1991 [2]. However, recruitment of centres and women to the trial was phased over a 5 year period in order to accommodate the additional workload within the NHS Breast Screening Programme. Women in the intervention arm of the trial are offered screening annually until the year of their 48th birthday. Consequently, screening in the trial is continuing until the end of 2004, and follow up for many years beyond this. The trial was designed to compare breast cancer mortality between the intervention and control arms at 10 years from each woman’s date of entry. It is well recognised that in a breast screening trial it will be many years from entry before any impact on mortality can be expected to become evident. This is due partly to the small number of deaths in the early years among cases diagnosed after entry, and partly to the effect of lead time [3]. In the AGE trial the timing of any such analysis is agreed with an independent Data Monitoring and Ethics Committee. Publishing mortality findings too early would result in wide confidence intervals and potentially misleading conclusions. Thus a mortality analysis must await accrual of the requisite amount of follow up. Sue Moss, Associate Director, Cancer Screening Evaluation Unit Institute of Cancer Research, Cotswold Road, Sutton, Surrey, SM2 5NG Howard Cuckle, Professor of Reproductive Epidemiology, University of Leeds Leeds Screening Centre,Gemini Park, Sheepscar Way, Leeds LS7 3JB, UK Competing interests : None declared Reference List 1. Thornton H. Screening without evidence of efficacy (Letter). BMJ 2004;328. 2. Moss S,.for the Trial Steering Group. A trial to study the effect on breast cancer mortality of annual mammographic screening in women starting at age 40. J.Med.Screening 1999;6:144-8. 3. Nystrom L, Andersson I, Bjurstam N, Frisell J, Nordenskjold B. Long-term effects of mammography screening: updated overview of the Swedish randomised trials. Lancet 2002;359:909-19. Competing interests: None declared |
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Hazel Thornton, Honorary Visiting Fellow, Department of Health Sciences, University of Leicester. "Saionara", 31 Regent Street, Rowhedge, Colchester, CO5 7EA
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All interventions will produce evidence of harms and benefits in individuals who receive them. It is essential that systems for full quantitative and qualitative data collection should be in place, particularly for interventions in healthy populations. The `AGE` Trial was designed to randomise 195,000 symptom-less women aged 40-41 at entry to study the effect of annual mammography, primarily on mortality. Randomisation ended in 1996 and screening will be completed by December 2004 when complete mortality data will be available. 53,000 were invited for annual screening for eight or nine years; a control group of 106,000 were `not invited`: an overall shortfall deemed acceptable by the Data Monitoring and Ethics Committee (DMEC). [1][2] No mention is made about morbidities (physical, psychological, emotional, social, financial), [3] although many thousands of women screened in their forties, both within and without this trial, and from other trials of mammography in this age group, have experienced its harmful consequences. An independent DMEC should take into account reliable quantitative and qualitative evidence available from all sources, not just those concerning effects on mortality within the trial itself. Whilst there are valid arguments in general for not publicising trial data until completion, screening in the `AGE` trial is almost complete. There is reliable evidence from other sources with 14-yr. follow-up that the likelihood of benefit is extremely small or non-existent; [4] there are also certain harms. There is also concern about contamination of findings by opportunistic screening in the control arm of the AGE trial. [1] We should all refer again to the Wilson and Jungner principles of screening [5] to ponder how unwise and unethical it has been to ignore them. Advocates of screening frequently insist that we must wait for deciades until the `true` effect on mortality is apparent after lengthy follow-up before publishing. In the meantime, millions of women are being harmed; million of £/$ expended; millions of people are going without basic healthcare. I repeat: is this ethical? Is it just? [1] Sue Moss. The `AGE` Trial: a study of the effect on breast cancer mortality of annual mammographic screening of women starting at ages 40- 41. NCRI. Booklet: Current National Trials 7th National Breast Cancer Trials Meeting, 21st November 2003. [2] NHS Cancer Screening Programmes: Breast Cancer. {http://www.cancerscreening.nhs.uk/breastscreen/research.html] [3] Sue Moss, Howard Cuckle. Timing of publication of AGE trial results. bmj.com rapid response 5th March 2004. http://bmj.journals.com/cgi/eletters/328/7438/521-a] [4] Cornelia J. Baines. Mammographic Screening: Are Women Really Giving Informed Consent? Journal of the National Cancer Institute. 2003 Vol. 95, No. 20. [5] Wilson JMG, Jungner G. Principles and practice of screening for disease. Public Health Paper. Number 34. Geneva, WHO. 1968 Competing interests: None declared |
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