[Markers of bone formation in children with osteosarcoma]

Among biochemical markers, which reflect bone remodeling and can be measured in blood, there are formation markers such as serum bone alkaline phosphatase (BALP) and osteocalcin (OC). Formation markers are considered to be useful in diagnosis and anticancer treatment of many metastatic bone diseases, but the clinical value of these markers in primary osseous tumours such as osteosarcoma is not yet recognized.

The aim of this study was the investigation of BALP activity and OC level in patients with osteosarcoma during clinical treatment.

We studied 22 patients (aged 11-19 years) with osteosarcoma, at diagnosis, during preoperative and postoperative chemotherapy and at the end of treatment. The control group consisted of 30 healthy age-matched children. The activity of BALP and the level of OC were measured in serum using ELISA kits.

Our results indicated that both tested parameters were lower during preoperative and postoperative chemotherapy (BALP, p<0.05; OC, p<0.01,p<0.001), in patients group than in controls. However we found higher value of BALP and OC also at diagnosis and during chemotherapy in same patients before occurrence of metastases. Moreover, we observed markedly higher activity of BALP (5:fold) and level of OC (2-fold) in patients with progression in comparison to the group with favourable prognosis, who responded to chemotherapy.

Our studies suggest, that investigation of formation markers, especially BALP could be useful in monitoring of osteosarcoma therapy and may be a valuable indicator of the progression of this disease. Further studies with long-term observation of investigated patients are necessary.