The aim of the study was to examine TRAP-5b as serum tumor marker for patients with primary malignant bone tumors.

In total 69 patients were included in protocol: 34 – with primary malignant bone tumors – 1st group, 35 – with non-oncologic pathology of bone tissue (12 – with benign bone tumors and 23 – with traumatic bone fractures) – 2nd group and 38 healthy donors – 3rd group. The distribution of patients according age and sex in all groups was similar. The level of TRAP-5b was examined by means of immunoassay method.

The low value (< 3,0 U/L) of TRAP-5b was found in 39% cases in 2nd group, in 31% cases of donors in 3rd group and only in 3% cases of patients with malignant bone tumors. High concentrations of TRAP-5b (> 6,0 U/L) were found in serum of only one patient from 2nd group and only one donor. At the same time TRAP-5b level more than 6,0 U/L was determined in 35% cases of patients with malignancies. The average TRAP-5b value was: 6,14±0,51 U/L in 1st group, 3,9±0,18 U/L in 2nd and 3,7±0,27 U/L in 3rd group. The marker level was higher in group of patients with osteolytic component of bone destruction, compared with group of patients with mixed type of destruction (7,74±0,73 U/L vs. 4,48±0,92 U/L).