Author Interviews, Breast Cancer / 17.09.2014
Study Finds Breast Cancer Screening Should Begin Around Age 40
MedicalResearch.com Interview with:
Blake Cady MD
Professor of Surgery (emeritus) at Harvard Medical School
Partners HealthCare, Harvard Medical
School institutions, Boston
Medical Research: What are the main findings of this study?
Dr. Cady: Our findings support mammography screening, and our data is consistent
with the randomized trials. Breast cancer screening with mammography is the most extensively researched screening method ever studied. Only one “randomized" trial failed to show reduced mortality, (Canadian NCSS studies), and there were major flaws in its design and execution that negate their results, as noted in multiple critical publications (volunteers, not geographic assignment, palpable masses detected at examination assigned to “screening” arm, large contamination bias (control group got screened anyway), and very poor quality of mammography). Yet it is this NCSS study that is cited by critics and the press. “Failure Analyses” look backward from death, rather than forward from assignment in randomized trials. The concept of failure studies is well established as noted in recent reports of air-bag failures in cars, and many industrial studies. Seat belt prevention of deaths was discovered by police recording injuries and deaths in crashes after the fact - a failure analysis - not by randomized clinical trials. In breast cancer, failure analyses have advantages of little cost, early results, simplicity, and convenience, compared to randomized trials. Since our results support findings from randomized clinical trials (RCT), they can be accepted as reliable and accurate.
Our findings show that about 71% of deaths from breast cancer occur in the approximately 20% of our patients not in regular screening programs, while only 29% of deaths occur in the 80% of women who were regularly screened by mammography. By extrapolation, women regularly screened have only about a 5% breast cancer mortality, but women not screened have close to a 50% mortality.
(This is my extrapolation from our data, not direct data from our “Failure Analysis”)
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