Several
biochemical markers of bone formation and
bone resorption have recently been developed. These markers have been evaluated for clinical utility in patients with
metabolic bone disease, including Paget disease and
osteoporosis, and for their potential use in
cancer patients whose disease has metastasized to bone. We have evaluated seven markers of bone turnover in the plasma and urine of 94 patients with newly diagnosed or progressive
malignancy with and without clinical evidence of bone
metastases. As determined by a positive bone scan and (or) bone survey, 30 patients had
metastases to bone; 51 patients had metastatic
cancer without overt bony involvement; and 13 patients had local disease without bone
metastases. To evaluate the predictive value of these markers in the metastatic population, we utilized a "Z-score" and logistic regression analysis to distinguish patients with documented bone metastatic disease from those patients without clinical evidence of bone
metastases. The higher the Z-score, the better the marker predicts the presence of bone
metastases. With this statistical approach, urine
N-telopeptide measurements had the highest Z-score and the most significant association with the probability of bone
metastases. Urine
deoxypyridinoline was the second most predictive marker of bone
metastases. Thus,
biochemical markers of
bone resorption might be of use to predict the presence of bone
metastases in
cancer patients and to monitor the efficacy of antiresorptive
therapy in patients treated for metastatic
bone disease.