Angiogenic biomarkers of response to treatment with peptide receptor radionuclide therapy in neuroendocrine tumours

Introduction: Neuroendocrine tumours (NETs) are a heterogeneous group of tumours, which is characterised by rich vascularisation. The role of angiogenesis in NETs has been widely researched. Peptide receptor radionuclide therapy (PRRT) is an effective treatment method for patients with disease progression in NETs. Due to the heterogeneity of NETs, the response to treatment varies. Currently, the finding of efficient markers helpful in assessing the response to treatment in NETs is crucial. The aim of this study was to assess chromogranin A (CgA) and angiogenic factors in gastro-entero-pancreatic (GEP) and broncho-pulmonary (BP) NET patients treated with PRRT. Material and methods: The study group included 40 patients with GEP NETs and BP NETs, who completed 4 cycles of PRRT. Serum levels of CgA and angiogenic factors such as vascular endothelial growth factor (VEGF) and its receptors (VEGF-R1, VEGF-R2, VEGF-R3) were assessed before and after 4 cycles of PRRT. All tests were determined using ELISAs. Results: The concentration of CgA, VEGF-R1, and VEGF-R2 decreased significantly, whereas VEGF-R3 increased significantly after PRRT. PRRT did not affect VEGF - it was similar before and after the radioisotope treatment. Based on AUROC, only VEGF-R1 exhibited good performance in distinguishing between NET patients before and after PRRT; the area under the curve (AUC) was 0.7. Conclusions: VEGF-R1 is a potential biomarker for assessment of the effectiveness of PRRT in NET patients.