Immunohistochemical study of p53, VEGF, Flt-1/VEGFR1 Ab-1, EGFR, HER-2/neu, Bax, and Cox-2 expression in osteosarcomas was carried out in 40 patients aged 16-70 years. Expression of p53 was detected in 27.5% tumors, VEGF in 15%, Flt-1/VEGFR1 Ab-1 in 97.5%, EGFR in 52.5%, HER-2/neu in 32.5%, Bax in 77.8%, and Cox-2 in 32.3% tumors. Multifactorial analysis showed that the expression of HER-2/neu (p=0.004), p53 (p=0.01), and Cox-2 (p=0.04) in osteosarcomas significantly correlated with unfavorable prognosis for overall survival, while HER-2/neu (p=0.02) and Cox-2 (p=0.003) with relapse-free survival. Analysis of HER-2/neu, p53, and Cox-2 expression in the primary tumor should be taken into consideration in the treatment of patients with osteosarcoma.

Serum levels of sRANKL, RANK, OPG, IL-8, IL-6, IL-16, MMP-2, and calcitonin were measured by ELISA in patients with malignant, borderline, and benign bone tumors and in healthy individuals (control). Serum levels of RANK, OPG, IL-8, IL-6, and the OPG/sRANKL ratio were significantly higher, while the level of MMP-2 was significantly lower in patients with bone tumors than in controls. Serum concentration of IL-16 in osteosarcoma patients was significantly lower than in chondrosarcoma patients. No significant differences between bone sarcomas of different differentiation were detected for any of the studied markers. Calcitonin level depended on the tumor location and type.

Serum levels of endostatin, placental growth factor (PlGF), and fibroblast growth factors-1 and -2 (FGF-1 and FGF-2) were measured in 58 patients with primary osteosarcomas before therapy and in 21 healthy subjects. The incidence of serum FGF-1 in bone tumors was 2.5 times higher than in healthy individuals (p=0.004); significant levels of FGF-2, PlGF, and endostatin were detected in all examined subjects. The mean serum level of endostatin in healthy individuals was significantly lower than in the total group of patients with bone tumors (p=0.005). The level of FGF-1 in osteosarcomas was significantly higher than in chondrosarcomas (p<0.05). No appreciable differences in FGF-2 levels were detected in patients with tumors of different histological structure. The mean serum content of PlGF was virtually the same in healthy individuals and patients with bone tumors. A significant relationship between serum PlGF level and maximum tumor size (p=0.008) was detected in osteosarcoma. No relationships between the levels of FGF-1, FGF-2, PlGF, and endostatin were detected in healthy subjects and patients with primary tumors of the bones. Differences in 3-year overall survival values of patients with bone sarcomas with different initial serum levels of FGF-1 and endostatin were detected.