Commentary on the Downside of Breast Screening
by Anthony B. Miller, MD, FRCP. Professor Emeritus, Dalla Lana School of Public Health, University of Toronto
When the 25-year report of the Canadian National Breast Screening Study (CNBSS) was published , showing no benefit from mammography screening, there was much dissension, and attempts to show that what we reported could not be true [2,3], to which we responded . The belief that “early” detection of a cancer is bound to be beneficial is entrenched in our society, people do not understand that the mere early detection of a cancer does not automatically result in benefit, the cancer may not have been destined to be fatal with modern therapy even when detected later by the woman herself, the cancer might never have progressed to become detectable by the woman if it had not been revealed by the mammogram, or, the cancer was destined to kill whatever stage it was detected because of its innate biology. Even if we accept that mammography screening reduces breast cancer mortality by 15-20% , and I do not, that means that 80% or more of the deaths from breast cancer destined to occur will still do so.
by Lorna Larsen RN, BScN, Team Shan President
Mammograms have been considered the gold standard in breast cancer early detection for decades. Despite limitations and risk/benefit concerns mammograms have detected breast cancers early and made a positive difference for a percentage of women diagnosed. The concern about false negative and false positive results of mammography has been part of the risk/benefit discussion over the past number of years and warrants review.
by Dr. Ellen Warner, MD, M.Sc., FRCPC, FACP
Screening the general population of women for breast cancer with mammography is a very appealing idea. Breast cancer is the commonest cause of cancer death in women worldwide. The great majority of women who develop breast cancer have no major identifiable risk factors. There is a strong correlation between breast cancer size at diagnosis and death from the disease. And, most importantly, mammography can often detect a breast cancer years before it is large enough to be detected by a patient or health care provider.
A Rational Approach To Breast Cancer Screening
by Martin J. Yaffe, PhD, C.M, Senior Scientist and Tory Family Chair in Cancer Research, Sunnybrook Research Institute, Professor, Depts. Medical Biophysics and Medical Imaging, University of Toronto, Director, Smarter Imaging Program, Ontario Institute for Cancer Research
Several times per year an article appears in the popular media, usually referring to a “new study” demonstrating that breast cancer screening is ineffective. And as has happened now, with the publication by Jorgensen et al. and the resulting media coverage, I am asked to comment on the “debate regarding the value of screening”. In fact, there really is no debate about the science, if one restricts oneself to studies that have been carefully conducted using appropriate methodology and analysis. The debate is really about values (those of women, health providers and government) in preventive medicine. Screening is expensive. Is the cost justified by the saving of lives and are the negative aspects of screening – abnormal recalls and negative biopsies – acceptable?
Overdiagnosis, Overdone: Unraveling Issues and Pitfalls
by Constantine Kaniklidis *, Research Director, No Surrender Breast Cancer Foundation (NSBCF) **
In a previous editorial on the mammography debate, I wrote: “that it is complex; that it is naïvely implausible to expect any decisive final resolution to the residual issues that will be convincing to the principle contending parties; and that behind it all, the devil is in the methodology”1. Almost two years later, the words stand true, but we have advanced significantly in illuminating the many dark cobwebbed corners of the debate. Center in that web is overdiagnosis (overdetection) with sister ills of false-positives and overtreatments, the harms that trouble – not illegitimately – so many critics of screening mammography, with heated disagreement about both the degree of overdiagnosis, and the validity of different estimation methodologies.
Mammography screening works
by Stephen W. Duffy, MSc, Wolfson Institute of Preventive Medicine, Queen Mary University of London
Since the 1960’s, hundreds of thousands of women have been enrolled in randomised controlled trials of breast cancer screening using mammography. It would be difficult to find a medical procedure which has undergone such extensive testing and scrutiny. The randomised trials show a significant reduction in breast cancer mortality, of the order of 20%, with invitation to screening. Since not all women invited to screening actually attend, it has been estimated that the effect of actually being screened is to reduce breast cancer mortality by 30-40%.