COMPASS- Cancer Outcomes in Multimorbidity: Pathway and System Study (360G-Wellcome-342255_Z_25_Z)

Multimorbidity is common at cancer diagnosis and can influence screening uptake, route to diagnosis, treatment decisions, and survival. Understanding how the presence, type, and complexity of long-term conditions shape cancer diagnostic journeys can identify patients at risk of delay, reveal mechanisms such as symptom masking or competing priorities, and inform interventions to shorten diagnostic intervals. The overarching aim of this PhD is to investigate how multimorbidity, measured in multiple ways, impacts cancer diagnostic pathways and outcomes. This PhD will use a multi-methods design. A systematic review will describe and analyse the current literature exploring the impact of pre-existing long-term conditions on diagnostic route and timeliness in people diagnosed with one of the four most common cancers in the UK (breast, prostate, lung and colorectal). Quantitative analyses of linked routine health data will then focus on pathways for bowel cancer, evaluating how individual and multiple conditions impact screening uptake, primary care clinical activity, diagnostic route and timeliness, stage at diagnosis, and survival. Finally, qualitative interviews with primary care professionals will explore how pre-existing conditions influence the management of suspected bowel cancer and identify strategies to improve detection in patients with multiple and complex health needs.