Bone turnover markers in primary and metastatic bone tumors.

Abstract

e23513 Background: The purpose of the study was to reveal the levels of biochemical parameters for assessing the intensity of bone metabolism in patients with primary and metastatic bone tumors. Methods: The study included 29 patients aged 55.9±12.17 years with primary (group 1, n = 12) and metastatic (group 2, n = 17) bone tumors. Group 2 included patients with breast cancer (2a, n = 10) and renal cancer (2b, n = 7) with a history of pathological fractures. Serum levels of the bone turnover marker osteocalcin, TSH, the resorption marker β-Cross Laps (C-terminal telopeptide) (Cobas e411, Japan) and calcium (Vitros 5600, USA) were measured before and after (day 14) organ-preserving treatment. The data were compared with that in non-cancer patients of similar age (n = 15) and evaluated in the Statistika 10.0 program. Results: Osteocalcin levels in group 1 prior to surgery was 1.74 times (p < 0.05) higher than in controls (13.56±1.35 ng/mL) and decreased by 35% (p < 0.05) compared to the initial values. In group 2, changes in osteocalcin levels were multidirectional: group 2a – 24% (p < 0.05) higher than in controls both before and after surgery; group 2b – similar to control values before surgery and decreased by 19% (p < 0.05) after it. Levels of β-Cross Laps in all patients before surgery were within the control range (0.49±0.02 ng/mL). After surgery, the levels in groups 1 and 2a did not change, while group 2b showed an increase in β-Cross Laps by 1.5 times (p < 0.05) and a decrease in calcium by 20% (p < 0.05) from the initial levels (2.33±0.09 mmol/L), which, along with a decrease in osteocalcin, could be the result of specific kidney damage. TSH in groups 1 and 2b was similar to controls, but initial TSH levels in group 2a were increased by 86% (p < 0.05) and did not change after surgery, as well as osteocalcin levels, which in the absence of changes in β-Cross Laps suggested a more favorable prognosis after organ-preserving treatment. Conclusions: Bone tissue remodeling processes are determined by the nature of the initial tumor. Measuring osteocalcin and β-Cross Laps in patients with specific bone lesions may be useful in assessing the risk of fractures.