“The potential benefits and harms of cancer screening – perspectives from the US Preventive Services Task Force”

Lecture by Professor Mark Ebell, University of Georgia, USA

Supported by the HRB Primary Care Clinical Trials Network Ireland

Prof Mark Ebell, a leading general practitioner and researcher in the US, gave a seminar in NUI Galway on cancer screening. He talked about the potential benefits and harms of screening, an overview of how the US decides what cancers should be screened for, compared the national cancer screening recommendations of Ireland and the US and finally reviewed in some detail the key issue of over diagnosis as a harm. Prof Andrew W Murphy, general practitioner in Turloughmore and Director of the HRB Primary Care Clinical Trials Network Ireland, stated that ‘Prof Ebell’s seminar was a great introduction to leading edge research internationally into ensuring that our cancer screening programs cause more good than harm. He provided practical advice onto how to achieve this. He highlighted that Irish cancer screening recommendations are currently congruent with best international practice – but need to be constantly reviewed.’

Prof Ebell noted that while there are many kinds of cancer, for only a few is there evidence that the potential benefits of screening outweigh the potential harms. While potential benefits are substantial for a small number of those screened (a death averted), all patients experience some degree of inconvenience, and many are subjected to the harms of biopsies and other follow-up tests. A new kind of harm, increasingly recognized and present with most kinds of cancer screening, is over diagnosis. As our technology has evolved, we are able to detect smaller and smaller lesions that may appear cancerous, actually do not behave like a cancer. About 1 in 5 persons who have a breast or lung cancer detected by screening would have lived a full life with the cancer never causing any symptoms (“overdiagnosis”).

Professor Mark Ebell is a graduate of the University of Michigan’s Medical School, Family Medicine Residency, and School of Public Health. He is currently a Professor in the Department of Epidemiology and Biostatistics in the College of Public Health at the University of Georgia. Professor Ebell is Editor-in-Chief of Essential Evidence and Deputy Editor of the journal American Family Physician. He is author of over 350 peer-reviewed articles and is author or editor of seven books, with a focus on evidence-based practice, systematic reviews, medical informatics, and clinical decision-making. Professor Ebell served on the US Preventive Services Task Force from 2012 to 2015, and in 2019 will be a Fulbright Scholar at RCSI in Dublin, Ireland.

Click here to watch Prof Ebell’s lecture.