Objective
To detect the expression of osteopontin (OPN) in benign and malignant bone tumors and investigate the prognostic influence of OPN expression on the outcome of osteosarcoma patients.
Methods
Fifty-seven osteosarcomas and 11 osteoblastomas as well as 5 bone specimens with remodeling sites were immunohistochemically analyzed for expression of OPN and cyclooxygenase-2 (COX-2).
Results
OPN was not detected in osteoblasts of remodeling sites. Osteoblastoma osteoblasts as well as osteoclastlike giant cells and osteosarcoma mononuclear cells showed variable staining. In osteosarcomas OPN and COX-2 expression correlated with each other (r = 0.390, P = 0.003, Spearman’s test). Although osteosarcoma patients with high COX-2 expression showed a trend towards shorter overall survival (P = 0.0841, log-rank test), OPN expression had no influence on patients overall or on disease-free survival.
Conclusion
Our data indicated that expression of this protein might be unregulated in bone neoplasia. Although OPN expression correlates with COX-2 expression in osteosarcomas, OPN expression does not provide predictive information about the outcome of osteosarcoma patients.