Neuroendocrine tumours: Understanding the patient experience and improving follow-up

Neuroendocrine tumours (NETs) of the small intestine (siNET) are slow-growing malignancies often diagnosed at an advanced stage. Despite their indolent nature, patients frequently experience significant symptoms, including carcinoid syndrome (CS) with diarrhoea, which impact their health-related quality of life (HRQoL). This thesis investigates the determinants of HRQoL in siNET patients, its prognostic value, and the role of somatostatin receptor imaging (SRI) in follow-up.The research encompasses four studies analyzing clinical and imaging data from a patient cohort at Skåne University Hospital, Lund. In the first study, specific bowel symptoms such as stool urgency and soiling were identified as key contributors to impaired HRQoL, especially within is social and role functioning domains. The second study examined the association between somatostatin receptor-expressing tumour volume (SRETV) and HRQoL in metastatic NET, revealing no correlation between QLQ-C30 Summary Score and SRETV and a weak correlation between SRETV and symptoms of the carcinoid syndrome.The third study assessed the clinical utility of routine somatostatin receptor PET-CT in follow-up of metastatic siNET and found that a significant proportion (86%) of imaging did not lead to major changes in treatment, suggesting a need for more tailored surveillance protocols. The study also identified six risk factors with independent association on risk for major change in treatment. The fourth study explored the predictive value of HRQoL on overall survival, demonstrating that lower HRQoL scores were independently associated with worse prognosis after adjustment for clinical confounders, supporting its role as a potential marker of progressive disease.This thesis emphasizes the importance of HRQoL assessment in routine clinical care and suggest avenues for optimizing patient management, including refined follow-up strategies and targeted symptom control of socially stigmatizing bowel symptoms.