β-Crosslaps as a Marker for Bone Metastases in Renal Cell Cancer

The aim of this study was to evaluate the diagnostic significance of the bone resorption marker β-Crosslaps for the detection of bone metastases in renal cell cancer patients. β-Crosslaps concentrations were measured in serum samples from 87 renal cell cancer patients. Of these, 35 men, 19 women, and 17 boys showed no bone involvement. 15 men and two women suffered from bone metastases. When comparing women with and without bone metastases by using an optimal cut off value (11.25ng/ml), the sensitivity of β-Crosslaps for detecting bone metastases was 100% and the specificity was 57.89%. Using an optimal cut off value (81.2ng/ml) in men, the sensitivity and specificity for detecting bone metastases was 93.33% and 91.42%, respectively. There was a significant increase (p < 0.01) in β-Crosslaps in patients with renal cell cancer as compared to healthy subjects. This difference existed even in the patients without bone metastases. Furthermore, the β-Crosslaps values increased with the tumor-node-metastases (TNM) system (T-value). β-Crosslaps were suitable as a diagnostic tool for the detection of bone metastases in men with renal cell cancer. In addition, the study showed a significant increase of the β-Crosslaps concentration in renal cell cancer patients without bone metastases, accompanied by an increase as the TNM stage (T-value) increased. β-Crosslaps could be useful as a tumor marker for renal cell cancer. Additionally a review of recent patents on tumor markers is provided.