Endocrine Abstracts

JOINT1158

Introduction: Neuroendocrine Tumors (NETs) remain a problematic area in endocrine oncology, due to their non-specific symptoms and the lack of reliable biomarkers. They are often diagnosed late, which leads to poor disease outcomes. Visfatin, an adipocytokine initially researched in metabolic disorders, has been linked with angiogenesis and tumorigenesis in various neoplasms. However, no studies in NETs were previously conducted. In this study, we aimed to analyze serum visfatin concentrations as a diagnostic biomarker in patients with NETs.

Material and Methods: We conducted a single-center, cross-sectional study of 77 patients with NETs (33 pancreatic and 44 small intestinal NETs) and 29 controls without NET diagnosis. Serum visfatin levels were measured using ELISA. Patient demographics and clinical characteristics were recorded for patient recruitment, with data on sex, age, NETs primary site, and WHO grade used for subsequent analyses. Group comparisons were performed using Mann-Whitney U and Kruskal-Wallis tests. Spearman’s rank correlation and multiple linear regression were used to compare the association between visfatin, and patient and tumor characteristics. ROC curve analysis evaluated visfatin’s diagnostic performance in distinguishing NETs patients and controls. Statistical analyses were conducted in Python using pandas, NumPy, SciPy, scikit-learn.

Results: Serum visfatin concentrations were significantly higher in patients with NETs compared to controls (median[IQR]: 6. 94[2. 11-236. 17] vs 1. 59[1. 1-9. 24] ng/ml, P = 0. 0233). ROC curve analysis showed moderate diagnostic performance (AUC=0. 68), with concentrations above 2. 11 ng/mL providing a sensitivity of 75. 3% and specificity of 58. 6%. In patients with NETs, visfatin levels did not differ between WHO grades (G1 vs G2, P = 0. 31), primary sites (pancreas vs small intestine, P = 0. 95), sex (P = 0. 89), age (P = 0. 13), and when stratified by both primary site and grade (P = 0. 178). Multiple linear regression confirmed no association between visfatin and age, sex, NETs primary site, and grade (R-squared=0. 036, p>0. 2 for all variables).

Conclusion: This is the first study to evaluate potential utility of serum visfatin as a diagnostic biomarker in NETs. Serum visfatin concentrations show moderate discriminatory ability between subjects with and without NETs, and appear independent of other tumor and patient characteristics. Further research should involve larger study groups and assess visfatin’s utility alongside and compared to other NETs biomarkers.

Keywords: Neuroendocrine neoplasms, visfatin, biomarkers, eNAMPT, PBEF1