Neuroendocrine tumors (NETs) are a rare group of cancers. Patients often present with metastatic and non-curable disease. Patients with NETs may experience various symptoms from the tumor mass, the output of hormones secreted by the tumor, and treatment accompanying side effects. The aim of this thesis was to measure and improve the clinical benefit of treatment and supportive care provided to patients with NET. An approach to improve quality of life (QoL) is to provide adequate information. We found that in patients with NET a web-based-tailored-support system did not improve QoL. Standard of care consisting of support and information provision by an oncology nurse and medical doctor could not be substituted by a web-based-system. We also investigated a personalized dietary advice with vitamin supplementation of deficient vitamins in somatostatin analog using patients with NET. The pilot-study showed this intervention was feasible. We found that these patients were at risk for vitamin A, D, E, K, B12 and niacin deficiencies, which were not easily corrected.
Furthermore, we showed that lesions with high 18Fluorine-L-dihydroxyphenylalanine ([18F]FDOPA) uptake could be detected in patients with NET on the [18F]FDOPA PET scan. This suggests that [18F]FDOPA PET scans can support selection of lesions with substantially higher [18F]FDOPA uptake, and probably higher excretion of neuroendocrine amines, for local treatment.
Finally, we analyzed the NET immune microenvironment. We demonstrated that NETs lack pre-existing immunity. This can have impact on future trials investing immunotherapies in patients with NETs.