The usefulness of determining the serum concentrations of vascular endothelial growth factor (VEGF) and its soluble receptor type 2 (sVEGF-2) in the differential diagnosis of adrenal incidentalomas.
[adrenal incidentaloma]
Angiogenesis plays an important role in tumour growth, progression and invasiveness. Vascular endothelial growth factor (VEGF) is a recognised angiogenesis-stimulating factor. Soluble VEGF receptors (sVEGFRs) have antiangiogenic properties. Recent studies have indicated that serum concentrations of these factors show a good correlation with the aggressiveness of these tumours in various organs. The aim of this study was to assess the usefulness of determining serum concentrations of VEGF and sVEGFR-2 in patients with adrenal incidentalomas.The study included 51 patients: 38 women aged 53.57 ± 10.12 years and 13 men aged 54.66 ± 12.73 years without a history of cancer but with non-functioning adrenal tumours incidentally detected on a CT scan. The analysis of the CT images included such morphological features of the tumour as: tumour size, tumour homogenicity, tumour density before and after administration of an intravenous contrast medium, and the value of percentage washout of the contrast medium from the tumour. Based on the above criteria, we identified a group of 40 patients with adrenal tumours who met the CT criteria for benign adenomas (Group 1) and 11 patients whose incidentally discovered tumours did not meet the radiological criteria for benign adenomas, thereby providing grounds for referring these patients for surgery (Group 2). The control group consisted of 20 healthy sex- and age-matched individuals.The mean serum concentrations of VEGF in the study and control groups were similar, although patients with adrenal tumours had significantly higher concentrations of sVEGFR-2 than healthy individuals. There were no significant differences in the mean concentrations of VEGF and sVEGFR-2 between the patients undergoing surgery (Group 2) and the patients not undergoing surgery (Group 1), or between the patients undergoing surgery (Group 2) and the control group. Postoperative histopathology of the resected adrenal tumours revealed benign adrenocortical adenoma in eight patients and the following in the remaining patients: adrenocortical carcinoma in one patient, phaeochromocytoma in one patient and ganglioneuroma in one patient. The adrenocortical carcinoma patient had the highest concentration of VEGF, while this patient's concentration of sVEGFR-2 was the lowest in the study group. In the patients diagnosed with ganglioneuroma and phaeochromocytoma, VEGF and sVEGFR-2 concentrations did not differ significantly from their mean concentrations in the study group. There were also no relationships between the serum concentrations of VEGF or sVEGFR-2 and the following parameters: tumour size, precontrast and postcontrast tumour densities or the value of percentage washout. Positive correlations were, however, identified between the concentration of VEGF and the concentrations of total cholesterol and LDL-cholesterol.Determining the serum concentrations of such angiogenesis markers as VEGF and sVEGFR-2 seems useful in the evaluation of the nature of incidentally detected adrenal masses (incidentalomas), especially in the preoperative differential diagnosis of adrenal masses that do not meet the CT criteria for benign tumours.
