Bone Sialoprotein Antibody to Estimate Risk of Bone Metastasis in Prostate Cancer Patients
Christos Philippou, Dirk Theegarten, Simon Gloger, Burkhard Ubrig, Bitterlich Norman, Naseva Emilia, Andreas Wiedemann, Hans-Jörg Sommerfeld, Abdulla Haji, Stathis Philippou
Background: Osseous metastasis is a typical site of metastasis in patients with prostate cancer.
Objective: To evaluate the role of bone sialoprotein (BSP) expression in prostate cancer patients with
bone metastasis.
Design, setting and participants: Immunohistochemistry and quantification were used to evaluate the BSP
expression in fine needle punctures of patients with prostate cancer. Data of patients were followed up for
7 to 9 years for detection of bone metastasis.
Results and limitations: 12.5% (84/673) of patients developed osseous metastasis. Of all patients, 20.8%
were BSP-negative (0% expression) and 22.2% presented high values of more than 40%. Patients with
bone metastasis had higher BSP expression than patients without bone metastasis (55.5 ± 19.7% vs. 25.7
± 24.9%;p< 0.001). 82.9% of patients with metastasis had a BSP expression of at least 40%, whereas no
metastatic patient had a BSP value of less than 20%. For BSP as a single parameter with a cut-off value of
50%, the overall sensitivity was 50% with a specificity of 81.6%.
Conclusions: BSP could be an indicator for the development of bone metastasis. Despite a high specificity,
the sensitivity is insufficient for the integration of BSP as a single parameter into clinical routine. Further
parameters must be added to the calculation to increase the sensitivity.
Patient summary: A typical site for metastasis of patients with prostate cancer is the bone. In this study,
we assessed a marker (bone sialoprotein) in prostatic tissue of patients with prostate cancer, which could
be an indicator for later development of bone metastasis.
