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.