Psychological Impact of the Galleri Test (sIG(n)al): Protocol for a longitudinal evaluation of the psychological impact of receiving a cancer signal in the NHS-Galleri Trial
Authors: Marlow Laura , Schmeising-Barnes Ninian , Warwick Jane , Waller Jo 
Published: June 2023

ABSTRACTIntroductionMulti-cancer early detection (MCED) blood tests look for cancer signals in cell-free deoxyribonucleic acid (cfDNA). These tests have the potential to detect cancers at an earlier (asymptomatic) stage, improving cancer outcomes. Any screening method needs careful consideration of the psychological harms prior to implementation. The aim of this research is to explore the psychological impact of having a cancer signal detected following an MCED blood test.Methods and AnalysisThe project is embedded in the NHS-Galleri trial (ISRCTN91431511;NCT05611632), a large clinical trial that has randomised over 140,000 members of the general population aged 50-77 1:1 to either the intervention (blood tested with MCED test) or control (blood stored) arm. This work focuses on participants in the intervention arm of the trial who have a cancer signal detected. All participants who have a cancer signal detected (expected to be around 700 assuming a 1% test positive rate) will be sent a questionnaire at three time points: soon after receiving their result, 6-months and approximately 12-months later. The primary outcome is anxiety, assessed using the short-form State Trait Anxiety Inventory (STAI-6). We will also assess the psychological consequences of screening (using the Psychological Consequences of Screening Questionnaire), reassurance and concern about the test result, as well as understanding of results, cancer risk perceptions and help- and health-seeking behaviour. A sub-sample of 40 participants (20 with a cancer diagnosis and 20 for whom no cancer was found) will be invited to take part in a one-to-one semi-structured interview to explore their experience in depth.Ethics and DisseminationEthical approval for this work has been granted by the Wales Research Ethics Committee as part of the NHS-Galleri trial (Ref 21/WA/0141). Results will be disseminated via peer-reviewed publication and presentations at national and international conferences.Strengths and limitations-This will be the first UK study to explore the psychological impact of an MCED screening blood test.-Multiple aspects of psychological impact will be considered across three time points ensuring our understanding of impact is wide ranging and extends beyond anxiety alone.-Test results are only communicated to participants if a cancer signal is found (in order to maintain blinding), so it is not possible to collect data from those receiving a negative result following their first blood test. Comparative information on psychological impact will need to be made with previous research in the cancer screening context.-The findings could be used to support policy making by the UK National Screening Committee (UKNSC) regarding recommendations for MCED screening in the UK in the future.-Data will be collected within the context of a clinical trial, so our findings will need to be interpreted with appropriate caution.