In 2003 researchers in Taiwan published the results of their study of urine deoxypyridinoline tests for detecting & monitoring metastatic bone lesions as shown in abstract below.
In the full text of their paper where various ranges of deoxypyridinoline levels are provided with their significance, they claim that the test can detect bone metastases 3 to 6 months before any other marker (as of 2003).
If this test is not surpassed by better more recent markers it might still be an easy non invasive & relatively inexpensive diagnostic tool.
http://www.annclinlabsci.org/cgi/con...stract/33/1/55
Diagnostic Value of Urine Deoxypyridinoline for Detecting Bone Metastases in Breast Cancer Patients
Hou MF, Lin SB, Yuan SS, Tsai LY, Tsai SM, Hsieh JS, Huang TJ.
Department of Surgery, Obstetrics and Gynecology, Kaohsiung Medical University, Taiwan, Republic of China.
Deoxypyridinoline (Dpd), a crosslink product of collagen molecules found in bone and excreted in urine during bone degradation, has been described as a marker of bone turnover in metastatic breast cancer. In this study, the urine deoxypyridinoline/creatinine (Dpd/Cre) ratio was determined by enzyme immunoassay in urine samples from 116 women with breast cancer. Bone metastases were confirmed by x-ray or CT scan, with follow-up > 6 mo. The urine Dpd/Cre ratio was significantly higher in patients with bone metastasis, compared to those without bone metastasis (p < 0.05). In patients with bone metastasis, ratios of urine Dpd/Cre were higher in those with multiple lesions, compared to those with a solitary lesion, and the values also reflected therapeutic response (p < 0.05). Serial monitoring of urine Dpd/Cre revealed that an elevation was correlated with disease progression. Patients with stable bone disease under effective therapy had significant diminution of the urine Dpd/Cre ratios, compared to those with progression of bone disease (p < 0.05). In conclusion, the urine Dpd/Cre ratio may be a useful marker for detecting bone metastases and evaluating their response to therapy