Bone turnover markers and bone scintigraphy in the evaluation of skeletal metastases

BACKGROUND: The aim of this study was evaluation of the clinical usefulness of bone scintigraphy and of serum bone turnover marker levels in the assessment of skeletal metastases. MATERIAL AND METHODS: We investigated 60 patients with suspected skeletal metastases. Serum level of bone-formation marker: amino-terminal propeptide of type I procollagen (PINP) and a bone-degradation marker: carboxy-terminal telopeptide of type I collagen (ICTP) were assessed with radioimmunoassays. Bone MDP-99m-Tc scans were performed as well. RESULTS: Hot spots were showed in 72% of patients. According to bone scintigraphy the patients were divided in to 3 groups: Group I -without hot spots (n = 16; 26%), Group II up to 10 hot spots (n = 25; 42%) and Group III more that 10 hot spots (n = 19; 32%). Mean serum level of ICTP was significantly higher in Group II than in Group I (p < 0.05), as well as in Group III compared to Group II (p < 0.001) and in Group III compared to Group I (p < 0.001). There is only one significant relationship in PINP levels-between Groups II and III. CONCLUSIONS: The levels of bone pathological degradation ICTP) and bone formation reflect the metastatic disease extent in bone. Serum ICTP level is more useful in staging metastasis. Significantly higher PINP reflects only a much disseminated process.