- Thomas Callender, public health registrar12,
- Katherine Payne, professor of health economics3,
- Nora Pashayan, professor of the epidemiology of ageing4,
- Anne Mackie, director of screening1
- 1Department of Health and Social Care, London, UK
- 2Division of Medicine, University College London, London, UK
- 3Manchester Centre for Health Economics, Division of Population Health, Health Services Research and Primary Care, University of Manchester, Manchester, UK
- 4Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK
- Correspondence to: T Callender t.callender{at}ucl.ac.uk
Tests using blood based biomarkers for the concurrent detection of multiple types of cancer in asymptomatic people are currently being trialled in the UK and elsewhere.1 This has raised the possibility of their adoption in population screening programmes. Multicancer testing has the potential to improve cancer survival, particularly for rarer cancers, through early detection. But this benefit has to be balanced against possible harms from false positive results; overdiagnosis; inaccurate predictions of, or indeed inability to, predict the cancer site; and cases where a cancer detected by testing is too small to be seen on imaging.23
Most discussion has considered the overall—aggregate—benefits and harms of screening programmes using multicancer tests. However, cancers behave remarkably differently between both individuals and cancer types. Differences in the natural history of disease have an important influence on the potential for one potential harm—overdiagnosis—when screening for multiple cancers simultaneously. The example of overdiagnosis illustrates why differences in cancer specific outcomes are relevant to both clinical practice and policy but risk being obscured by a focus on aggregate metrics to evaluate multicancer tests.
Early cancer detection with multicancer tests
Stage of cancer at diagnosis affects survival, making early detection through screening a research and policy priority. Cancer causes 28% of all deaths in England and 42% of premature deaths among people aged 40-70 years.4 Around two thirds of deaths from cancer in men and half of those in women are from cancers for which there are no screening programmes.4
Developing cost effective screening programmes for single rarer cancers is challenging. As the number of screening programmes and ensuing tests expands, the burden these programmes place on individuals increases, as does the …
