Jornal de Biomarcadores Moleculares e Diagnóstico

Prognostic Value of Bone Markers in Patients with Carcinoma

Abstract

Nicole Zulauf, Marcus D Speda, Gerhard M Oremek and Ingo Marzi

Background: We investigated the usefulness of bone markers, respectively Alkaline Phosphatase (AP) and Tartrat Resistant Acid Phosphatase 5b (TRACP 5b) for diagnosis, treatment and monitoring of patients with carcinoma of different origin. AP is a marker of bone formation, while TRACP 5b is a marker of bone resorption. The isoform 5b of the enzyme TRACP is expressed by osteoclasts and can be measured in blood. Objectives: The aim of this study was to evaluate the prognostic value of the bone markers AP and TRACP 5b to detect bone metastasis and pathological bone metabolism. Materials and

Methods: Our study comprised 101 patients with positive tumor markers. Sera of these patients were collected and the bone markers AP and TRACP 5b were determind. TRACP 5b was measured by a colorimetric test which determines the TRACP 5b by using the phophatase activity of this enzyme by dephosphorylation of p-Nitrophenylphosphate (pNPP). The test is a two site immunoassay by Medac Diagnostika, Germany.

Results: The sensitivity of AP in our study to detect bone metastasis is 52.9%, the specificity is 53.9%. TRACP 5b shows a sensitivity of 64.7% and a specificity of 70.9%. An elevated TRACP 5b activity is associated significantly with bone metastasis in our study groups (p=0.01). In patients with chronic elevated levels of liver enzymes we could see a significant elevation of TRACP 5b (p=0.005).

Conclusion: In conclusion TRACP 5b is more sensitive and specific to detect bone metastasis and bone turnover than the Alkaline Phosphatase. In patients with multimorbidity the origin of AP is not clear due to its multiorganic appearance. The levels of TRACP 5b are elevated in patients with bone metastasis and in patients with chronical dysfunction of the liver. TRACP 5b might be helpful in the diagnostic procedure of tumor-patients to detect bone metastasis. Moreover TRACP 5b seems to be helpful to indicate oncological patients with early dysfunctions in bone metabolism and helps to induce early treatment to these patients.