Bone markers in prostate cancer (PC) patients: Biologic criteria to identify patients at risk of developing distant metastases

Abstract

e16069 Background: Currently, there are no specific serum and/or urinary bone markers able to accurately identify PC patients with hormone-refractory disease and/or those with distant metastases. Methods: Four categories of PC patients were defined as follows: A. hormone-sensitive without distant metastases; B. hormone-sensitive with metastases; C. hormone-refractory without metastases; D. hormone-refractory with metastases. The serum bone markers investigated were osteogenesis-related [Osteocalcin (OC), procollagen type 1 amino-terminal propeptide (P1NP), bone alkaline phosphatase (BALP)], osteolysis-related [beta collagen 1 carboxyterminal peptide (βCTX), carboxyterminal telopeptide type 1 collagen (1CTP), tartrate resistant acid phosphatase (TRAP)] or osteoclastogenesis-related [osteoprotegerin (OPG)]. Receiver Operating Characteristic (ROC) curves and the Area Under these curves were used to estimate the overall accuracy of each marker in discriminating between the four categories (A vs. BCD; B vs. ACD; C vs. ABD and D vs. ABC) with no adjustment for multiplicity. Parametric (Student's t-test) and non-parametric (Kruskal- Wallis) tests were conducted too. All statistical analyses were performed by means of SPSS v 16 (SPSS Inc). Results: Data were from 40 consecutive PC patients treated at the Georges Pompidou European Hospital in Paris, France and who were equally distributed between categories. Hormone-refractory patients with distant metastases were accurately identified by P1NP, 1CTP and TRAP. The respective areas under the ROC values were 0.76, 0.84 and 0.79 (all Pvalues less than 0.01). None of the markers identified category B of patients. Conclusions: Some bone-related serum markers may be associated with the onset of hormone-refractory status and distant metastases. They should be prospectively validated in a larger cohort of patients. No significant financial relationships to disclose.