The modeling of multicancer early detection (MCED) tests' residual risk and the challenges of MCED evaluation and implementation

Attitudes to multi-cancer early detection (MCED) blood tests for population-based screening: A qualitative study in Great Britain

BACKGROUND

Trials are underway to test the clinical utility of multi-cancer early detection (MCED) blood tests for screening asymptomatic individuals. We sought to understand the acceptability of MCED blood test screening and potential barriers and facilitators to participation among the general public.

METHODS

We conducted eleven semi-structured online focus groups with 50-77-year-olds (n = 53) in April-November 2022. Participants were purposefully sampled to include a mix of socio-economic and ethnic backgrounds as well as people who would not want 'a blood test for cancer'. Participants were shown information about MCED blood tests. Transcripts were analysed using reflexive thematic analysis.

RESULTS

Participants showed enthusiasm for MCED screening. Perceived benefits included procedural familiarity and the potential to screen for many cancers. Enthusiasm was driven by beliefs that cancer is a real and increasing risk (both at population level and personally with age) and that early detection reduces treatment burden and cancer mortality. Some felt they would not want to know if they had cancer. The potential for MCED tests to raise anxiety was a concern, especially in a false-positive scenario. Participants wanted to avoid unpleasant and unnecessary procedures. The initial blood test was deemed "less invasive" than current screening tests, but potential follow-up procedures were a concern. Views on MCED screening were influenced by wider factors including dislike of uncertainty, desire for choice and control over one's health, and existing relationships with the NHS.

CONCLUSION

The introduction of MCED screening is likely to be appealing due to the simplicity and familiarity of the primary test procedure. Test accuracy needs to be high to facilitate acceptability and should be communicated from the outset. Some people would rather not know if they have cancer, and MCEDs will not appeal to all.

Multi-Cancer Early Detection: The New Frontier in Cancer Early Detection

The new generation of cancer early detection tests holds remarkable promise for revolutionizing and changing the paradigm of cancer early detection. Dozens of cancer early detection tests are being developed and evaluated. Some are already commercialized and available for use, most as a complement to and not in place of existing recommended cancer screening tests. This review evaluates existing single- and multi-cancer early detection tests (MCEDs), discussing their performance characteristics including sensitivity, specificity, positive and negative predictive values, and accuracy. It also critically looks at the potential harms that could result from these tests, including false positive and negative results, the risk of overdiagnosis and overtreatment, psychological and economic harms, and the risk of widening cancer inequities. We also review the large-scale, population-based studies that are being launched in the United States and United Kingdom to determine the impact of MCEDs on clinically relevant outcomes and implications for current practice.