Complex biological pathways including angiogenesis, invasion, osteoclastic activation and bone matrix degradation are involved in the formation of bone metastasis (BM). The aim of our study was to investigate the cross-sectional and longitudinal associations of a panel of 12 serum biochemical markers reflecting biological pathways underlying BM development. In a cross-sectional study, we investigated 29 patients with primary breast carcinoma without BM (BC/BMÀ), 28 patients with breast carcinoma and BM (BC/ BM þ ) and 15 healthy women. In longitudinal analyses, we investigated 34 patients for whom serum was obtained a two different time points: at the time of primary BC diagnosis and after a median time of 3 years. During this follow-up, 15 patients developed BM, whereas the other 19 remained free of BM. In patients who developed BM, the second samples were obtained before BM was documented by bone scan. The cross-sectional analyses have shown all biochemical markers to be significantly elevated in patients with BM, when compared to the patients without BM and healthy controls, except TGFb1 that was significantly decreased. Multivariable analyses showed that only the bone resorption markers TRACP 5b, CTX and ICTP, and the marker of angiogenesis VEGF were independently associated with BM. Those markers correctly distinguished 85% of BC patients with or without BM from normal individuals. Longitudinal analyses showed that patients with primary BC who developed BM during follow-up had higher levels of TRACP5b ( þ 95%, P ¼ 0.08) at the time of primary diagnosis, those patients had also a higher increases of ICTP (P ¼ 0.006), MMP-7 (P ¼ 0.004) and TIMP-1 (P ¼ 0.017) during follow-up than patients who did not progress toward bone metastasis. This study provides evidence of increase and interrelationship of circulating markers of angiogenesis, invasion and bone resorption in patients with BC with and without BM. Markers of bone resorption have the highest independent diagnostic value for detecting and potentially predicting BM in breast carcinoma patients. Bone is one of the most common sites of metastasis for certain types of tumours, especially prostate, breast and lung carcinoma (Mundy, 2002). Breast cancer progression to bone is a defining feature of a highly malignant tumour and the major cause of cancer-treatment failure. Early detection of bone metastasis is critical for clinical management and accurate staging of tumours. Currently there is no a simple way to reliably detect and predict which patients will develop bone metastasis. The detection of bone metastases relies on imaging technology, but novel approaches based on biomarker assessments are under intense investigation. Increasing body of data suggests that metastatic dissemination is site specific (Horak and Steeg, 2005) and that distinct molecular factors regulate bone metastasis formation (Yin et al, 2005). A multifactorial and multistep process of bone metastasis formation involves several biological mechanisms including angiogenesis, invasion through...

Fracture efficacy of PTH and alendronate (ALN) is only partly explained by changes in BMD, and bone collagen properties have been suggested to play a role. We analyzed the effects of PTH(1-84) and ALN on urinary ␣␣/␤␤ CTX ratio, a marker of type I collagen isomerization and maturation in postmenopausal women with osteoporosis. In the first year of the previously published PaTH study, postmenopausal women with osteoporosis were assigned to PTH(1-84) (100 g/d; n ‫ס‬ 119), ALN (10 mg/d; n ‫ס‬ 60), or PTH and ALN together (n ‫ס‬ 59). We analyzed patients on ALN alone (n ‫ס‬ 60) and a similar number of patients assigned to PTH alone (n ‫ס‬ 63). During the second year, women on PTH in the first year were reallocated to placebo (n ‫ס‬ 31) or ALN (n ‫ס‬ 32) and women with ALN continued on ALN. During the first year, there was no significant change in ␣␣/␤␤ CTX ratio with PTH or ALN. At 24 mo, there was a marked increase of the ␣␣/␤␤ CTX ratio in women who had received PTH during the first year, followed by a second year of placebo (median: +45.5, p < 0.001) or ALN (+55.2%, p < 0.001). Conversely, the ␣␣/␤␤ CTX ratio only slightly increased (+16%, p < 0.05) after 2 yr of continued ALN. In conclusion, treatment with PTH(1-84) for 1 yr followed by 1 yr of placebo or ALN may be associated with decreased type I collagen isomerization. The influence of these biochemical changes of type I collagen on bone fracture resistance remains to be studied.

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