by Daniel B. Kopans, M.D., F.A.C.R., F.S.B.I, Professor of Radiology Harvard Medical School, Founder – Breast Imaging Division – Massachusetts General Hospital
“ALTERNATIVE FACTS” AND BREAST CANCER SCREENING
“Alternative Facts” (AF) recently appeared as an outrageous concept in the “political arena”. What most do not realize is that “alternative” facts have been promulgated for decades by those seeking to reduce access to breast cancer screening. This has led to the pseudo “debate” about screening that has persisted for decades due to the “alternative facts” that have been manufactured to keep the “debate” going. Each time an “alternative fact” has been generated to cast doubt on screening, it has been refuted by science ([i]). Unfortunately, as each (true) fact has been established, new “alternative facts” have been manufactured. The article in the Annals of Internal Medicine cited by Nicholas Bakalar in the New York Times is an example of misinformation that got past poor peer review at a major journal and was published despite its lack of scientific rigor. The study from Norway ([ii]), cited by Mr. Bakalar ([iii]), claiming massive “overdiagnosis” due to mammography had no data on who actually had mammograms and no data on which cancers were detected by mammography. How can a test (mammography) be faulted when the “investigators” had no information on who actually had the test? In an earlier, scientifically more rigorous study from Denmark, Njor, et al looked at actual individual patient data and they found that there was little if any “overdiagnosis” due to screening ([iv]) and, another study found, contrary to the conclusions of the paper reviewed by Bakalar, that screening had in fact resulted in a marked decline in deaths from breast cancer in Denmark ([v]).
Overdiagnosis, Overdone: A Patient Summary
by Constantine Kaniklidis *, Research Director, No Surrender Breast Cancer Foundation (NSBCF) **
Understanding – and Measuring – Overdiagnosis Overdiagnosis occurs when the patient, were it not for screening, would have died of some other non-cancer cause without ever having been diagnosed with malignancy. Overdiagnosis estimates are fraught with many complex limitations and challenges, but overdiagnosis estimates can be “normalized” by drawing on only studies restricted to actual screening-attendant women (as opposed to only screening-invited women) and which also control for the major known confounding factors. The EUROSCREEN review (2 million women age 50 or older in 18 countries) which met these requirements found overdiagnosis as being just 6.5%, and autopsy studies find only a small degree of overdiagnosis (under 10% total, just 1.3% for invasive breast cancers only).
The benefits of breast screening are doubtful and the harms important.
Karsten Juhl Jørgensen, MD, DrMedSci, Deputy Director, The Nordic Cochrane Centre, Rigshospitalet, Copenhagen, Denmark.
Breast cancer screening has been disputed for many years. The origin of the dispute is the conflicting results reached by the nine original randomised breast screening trials. One of these trials estimated a 42% reduction in breast cancer mortality while others estimated no reduction, or only a smaller benefit . The most important harm is also disputed. As for prostate cancer screening, there is now general agreement that breast screening leads to the detection of some tumors that would not have been detected or caused health problems in the absence of screening [2,3,4]. The dispute relates to how many such overdiagnosed tumors there are.
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.