Features of the content of components of the vascular endothelial growth factor system in the blood of men with recurrent soft tissue sarcomas.

e23550 Background: Soft tissue sarcomas (STS) have been studied to a lesser extent than tumors of epithelial origin. The main problem with STS is its frequent recurrence. The aim of this study was to investigate changes in the blood levels of VEGFA, VEGFC, and sVEGFR3 in men with primary STS and its recurrences, taking into account the degree of tumor differentiation. Methods: The study included 30 men diagnosed with STS of the extremities: 14 men with primary STS (T2bN0M0) and 16 men with relapses after previous combined treatment (surgery and radiation) completed more than a year ago for primary disease or no more than two episodes of STS relapses (T2bN0M0). Histologically, most STS were liposarcomas. The average age of patients was 58.1±5.3 years. Well- and moderately differentiated tumors (G1-2) were present in 7 men with primary STS and in 8 patients with relapses, the rest had poorly differentiated and undifferentiated tumors (G3-4). The control group included 10 age-matched men without cancer. Blood samples collected from patients before treatment were analyzed using ELISA for the levels of VEGFA (eBioscience, Austria), VEGFC (ThermoFisher Scientific, USA), and sVEGFR3 (eBioscience, Austria). The results were statistically processed in accordance with general recommendations for medical research. Results: In all patients with STS, the level of VEGFA in the blood did not depend on G: in the primary process, it increased twofold compared to donors, and in relapses, it decreased threefold and became 6.0 times lower than in the primary process. Serum levels of VEGFC and sVEGFR3 depended on G and the STS episode. In primary STS G1-2, the content of VEGFC in the blood decreased by 1.4 times (p < 0.05), and sVEGFR3 increased by 2.0 times; in STS G3-4, the content of VEGFC in the blood increased twofold, the level of sVEGFR3 did not change. In patients with relapses of STS G1-2, the content of VEGFC in the blood increased by 1.5 times (p<0.05), while with relapses of G3-4 it decreased by 1.5 times (p<0.05) compared with donors, while the level of sVEGFR3 did not change in anyone. Conclusions: The obtained results reflect a complex picture of tissue and systemic restructuring associated with the development of primary and recurrent STS of the extremities, indicate a possible change in the functional status and informative value of the components of the VEGF system during STS recurrence, expand our understanding of the genesis of tumors of mesenchymal origin, and allow us to determine directions for further research.