The concentrations of vascular endothelium growth factor and angiogenin were measured by enzyme immunoassay in the sera of healthy subjects and patients with osteosarcoma and Ewing's tumor with consideration for the main clinical and morphological characteristics of the diseases. The studied angiogenic factors were characterized by high individual variability in both healthy subjects and age- and sex-matched patients with primary bone sarcomas. The level of endothelial growth factor was higher in control women than in men. The highest concentration of endothelial growth factor was detected in male patients with Ewing's tumor. Possible involvement of vascular endothelium growth factor and angiogenin in the pathogenesis of osteosarcoma and Ewing's tumor is discussed.

Comparative enzyme immunoassay of matrix metalloproteinases (MMP-2, -7, -9) and their tissue inhibitor-1 (TIMP-1) in the sera of 26 healthy individuals and 54 patients with primary osteal tumors before therapy revealed elevated TIMP-1 levels in the patients with classical central and periosteal osteosarcomas in comparison with the control. In patients, the level of MMP-9 significantly decreased compared to that in healthy individuals, while the levels of MMP-2 and MMP-7 remained unchanged. No differences in serum levels of MMP and TIMP-1 associated with gender, age, primary osteal tumor location and size were detected. Overall 3-year survival of patients with classical central osteosarcoma with serum level of MMP-9 below its median was higher than that of patients with MMP-9 level equal to above the median (90.9 ± 8.7 and 50.8 ± 23%, respectively).

The content of components of the RANK/RANKL/OPG system, the key regulator of homeostasis in the bone tissue, in blood serum samples from 199 patients with primary bone neoplasms and 131 practically healthy volunteers was measured by ELISA. Borderline giantcell tumor of the bone with high osteoclastogenic and osteolytic activity is characterized by an increase in the level of all components of this system and highest ratio of sRANKL/OPG in the blood serum. Study indexes in patients with various benign neoplasms and tumor-like bone lesions were lower than in patients with giant-cell tumor. The patients with malignant bone tumors could be divided into 2 subgroups with opposite indexes of the RANK/RANKL/OPG system. The patients with osteosarcoma and Ewing sarcoma had a low level of sRANK, but a high level of sRANKL. The patients with chondrosarcoma and chordoma had a high level of sRANK, but a low level of sRANKL.