Serum Concentrations of Selected Biological Factors as a Potential Tool for Detecting Recurrence in Endocrine Tumors—A Pilot Study

<b>Objectives:</b> The current standard of care for endocrine tumors includes a personalized diagnostic and therapeutic approach aimed at the early detection of tumor recurrence after radical surgery. Assessment of tumor-associated biological factors in serum may be useful in patient management. The aim of this study is to determine whether any of the selected growth factors (VEGF, FGF), lectins (Galectin-1, Galectin-3), proteins (Fascin), or TNF-α measured in serum may serve as a potential marker of recurrence. <b>Methods:</b> A total of 68 cases, including 43 patients with disseminated endocrine neoplasm (neuroendocrine tumor (NET) 30 cases, medullary thyroid cancer (MTC) 6 cases, adrenal neoplasm 7 cases) and 25 healthy participants, were included in the analysis. Serum concentrations of TNF-α, Fascin, VEGF, Galectin-1, Galectin-3, and FGF were determined in all cases. The results were compared between groups. <b>Results:</b> A comparison between all patients and controls revealed differences in TNF-α concentrations (2.88 vs. 0.93 (ng/mL), <i>p</i> = 0.008). When comparing the concentrations of the measured factors between the subgroups (classified by tumor type) and the control group, differences were found for TNF-α (<i>p</i> = 0.007) and Fascin (<i>p</i> = 0.035). In the case of Fascin, differences were found for MTC and adrenal neoplasm patients (0.52 vs. 5.28 (ng/mL), <i>p</i> = 0.048), as well as MTC and NET patients (0.52 vs. 5.59 (ng/mL), <i>p</i> = 0.007), while the differences between NET patients and controls were close to significance (5.59 vs. 3.67 (ng/mL), <i>p</i> = 0.076). For TNF-α, significant differences were found between NET patients and controls (2.88 vs. 0.03 (ng/mL), <i>p</i> = 0.005) as well as between MTC patients and controls (2.77 vs. 0.93 (ng/mL), <i>p</i> = 0.004). <b>Conclusions:</b> Serum concentrations of selected proteins and growth factors (Fascin, TNF-α) are significantly higher in those with disseminated endocrine tumors compared to healthy controls. More studies are needed to determine the role of these selected proteins and growth factors in the early detection of NET/MTC recurrence.