The Levels of Bone Alkaline Phosphatase (BALP) and Soluble Epidermal Growth Factor Receptor-2 (ECD/HER-2) in Pediatric Patients with Osteosarcoma During Clinical Treatment

AIM: The aim of this study was to assess the usefulness of bone-specific alkaline phosphatase (BALP) and the extracelluar domain of human epidermal growth factor receptor 2 (ECD/HER-2) measurements in pediatric patients with osteosarcoma as prospective prognostic and predictive markers for monitoring the treatment and early detection of disease recurrence. MATERIAL AND METHODS: We studied 22 patients (5 girls, 17 boys) aged 7-20 years with osteosarcoma (OS) treated at the Institute of Mother and Child in Warsaw. All the patients were evaluated for the serum levels of BALP and ECD/HER-2 before treatment, during pre- and postoperative chemotherapy and after the completion of treatment. Healthy children (n=22) were the reference group. The levels of BALP and ECD/HER-2 were measured using immunoenzymatic methods. RESULTS: The values of BALP and ECD/HER-2 proteins were higher (p<0.01; p<0.05, respectively) in patients with osteosarcoma at the time of diagnosis compared with the control group. The values of both markers significantly decreased during chemotherapy in most patients with remission. In contrast to ECD/HER-2, the value of BALP after therapy was higher in patients with progression than with remission (p<0.001). CONCLUSIONS: Our results demonstrate the different pattern of BALP and ECD/HER-2 proteins during clinical treatment in patients with osteosarcoma. Higher values of BALP may characterize the progression of the disease and unfavourable prognosis. Further longitudinal studies are necessary to confirm the prognostic values of BALP and ECD/HER-2 proteins in this group of patients.