Cancer Screening Trials: Weighing the Harms Interview with:
Bruno Heleno, PhD fellow
Research Unit for General Practice and Section of General Practice, Department of Public Health, University of Copenhagen, Øster Farimagsgade 5, PO Box 2099, 1014 Copenhagen K, Denmark What are the main findings of the study?

Answer: In a literature review of cancer screening trials of a wide range of screening interventions, we found that trials seldom report the information necessary to weigh benefits against harms. Were any of the findings unexpected?

Answer: Overdiagnosis was reported in 7% of 57 cancer screening trials. False-positives were reported for both trial arms in 4% of the trials, and they were reported for at least the screened arms in 18% of the trials. These are the harms more directly related with screening; yet, according to our criteria, they were reported in a minority of trials. What should clinicians and patients take away from your report?

Answer: We found that the harms of screening were poorly reported in randomized trials, the study design that can provide the best quality evidence of the effects of screenings. Healthcare decision makers, healthcare practitioners, and, ultimately, patients therefore cannot make informed choices about cancer screening as the information about benefits is more readily available and likely to be of higher quality than the information about harms. This is problematic as many cancer screening programs have important associated harms. What recommendations do you have for future research as a result of this study?

Answer: Researchers, ethical committees with responsibility about trials, and funders need to reflect and agree on which is the minimal information about harms that should be reported for every upcoming trial of cancer screening. This will bring transparency and will help provide the evidence required for informed decision making.

Quantification of harms in cancer screening trials: literature review

Heleno B ,Thomsen MF ,Rodrigues DS ,Jørgensen KJ ,Brodersen J. Quantification of harms in cancer screening trials: literature review. BMJ 2013;347:f5334