Breast cancer screening

Breast cancer screening To the Editor: Those caring about breast cancer control have been eagerly awaiting publication of the Australian pilot projects on mammography screening_ It has been a pleasure to read the article by Dr Rickard and colleagues' because the question of reproducibility has been a matter of some concern to the Australian authonnes. The success of the programme in Sydney provides further evidence that well trained and dedicated medical personnel can achieve high-quality results. We fully concur with the authors that "the need for stringent quality control cannot be overemphasised" _ The editorial comment by Dr Hirst and Dr Kearsley.' regardless of their good intentions, is woefully unbalanced and demonstrates their inability to evaluate the data published on breast cancer screeninq. In our opinion, they appear to have suppressed the evidence for benefit and overemphasised the so-called potential for harm. To begin with, the title of their comment suggests that the Sydney project is the only one in Australia. Even if this is the first one to be published, it is no secret that the other pilot projects are also doing an outstanding job. It is incorrect to give the impression that two of the randomised controlled trials have failed only because they had not shown a statistically significant reduction in breast cancer mortality when prematurely published. The wide range of the confidence intervals of these two particular trials justifies neither positive nor negative conclusions at this stage of their evaluation. Contrary to the opinion of Hirst and Kearsley, the International Union Against Cancer (UICC) Project on Screening for Breast Cancer concluded that "The results of 2 randomised studies demonstrate conclusively that mas screening for breast cancer can reduce mortality from breast cancer ... Current data are insufficient to determine whether appreciable extra benefit derives from adding physical examination to mammography.'" In this light, the assertion that palpation would reduce costs is unrealistic; on the contrary, clinical examination would considerably decrease specificity and predictive value, thus greatly increasing the cost of the programme. Also, it is absurd to state that the palpable tumours "presumably could therefore have been detected through existing medical services" when these tumours, in fact, were not detected until after mammography had been performed. Anxiety about breast cancer is already high in the Western world. Therefore, the beneficiaries of screening are not only those women whose breast cancers are diagnosed in the preclinical stage, but also the overwhelming majority of participants who do not have the disease. Thus, contrary to Hirst and Kearsley, in our opinion the potential for benefit is considerable (numerically) and the potential for harm, although real, is restricted to a fraction of the attendees. The best antidote to the existing anxiety about breast cancer is to offer women an opportunity of knowing, at regular intervals, that they do not have the disease; and if they do, that their risk of dying from it will be significantly reduced. We fully agree with Hirst and Kearsley that a high participation rate is desirable, and that informing the public in a balanced, professional manner is necessary to achieve this aim. We are concerned that their contribution to this dialogue, overemphasising the negative and suppressing the positive, may be detrimental to the sincere efforts of many individuals to control breast cancer in Australia. The questions raised throughout this "editorial comment", including benefit v. risk and cost, monitoring and evaluation systems, evaluation of the mortality data, performance measures for screening programmes, etc. have been extensively covered in the literature. We suggest that Hirst and Kearsley get better acquainted with this literature and also evaluate it in a more rational manner. Laszlo Tabar, MD Director. Department of Mammography Falun Central Hospital 79182 Falun. Sweden Peter B Dean, MD Associate Professor of Radiology Faculty of Medicine. University of Turku 20520 Turku, Finland R,ckard MT. lee W. Read JW. el at Breast cancer diaqnosis by screermq mammography early results of the Central Sydney Area Health Service Breast X-ray Programme Med J Aust 1991: 154 126-131 2 Hirst C, Kearsley JH. Breast cancer screening: "one swallow doth nol a summer make Med J Aus! 1991: 154 76-78 3 Day NE. Baines CJ. Chamberlain J. et al UICC project on screening for breast cancer: report of the workshop on screening for breast cancer Int J Cancer 1986; 38 303-308