title: Bone turnover markers as predictive tools for skeletal complications in men with metastatic prostate cancer treated with zoledronic acid.
abstract: BACKGROUND
  Bone turnover markers are helpful to diagnose bone metastases. The aim of this study was to evaluate the usefulness of these markers in prostate cancer patients with bone metastases before and during the treatment with zoledronic acid as predictive and monitoring tools of skeletal-related events (SRE).
  
  
  METHODS
  One hundred seventeen prostate cancer patients with bone metastases and treated with zoledronic acid (4 mg every 4 weeks) were examined. Fifty-six patients were with and 61 patients without SRE during a 60-week study. Total and bone-specific alkaline phosphatase, and amino-terminal procollagen propeptides of type-I-collagen (PINP), cross-linked N-terminal (NTx), cross-linked C-terminal telopeptides of type-I-collagen (ICTP), and C-terminal telopeptides of type-I-collagen as well as prostate-specific antigen (PSA) were measured before and 12, 24, 36, 48, and 60 weeks after starting treatment.
  
  
  RESULTS
  Higher baseline concentrations were observed in the SRE group. The bone markers except for ICTP and tALP decreased to 20-80% of the baseline values at week 12 after the drug administration showing a generally higher decline in the non-SRE group except for NTx. At all time points during treatment higher and increasing concentrations of bone markers were observed in the SRE group compared with non-SRE group. Cox regression models with clinical data and bone markers showed the baseline NTx concentration as predictor of SREs. During the study, percentage changes of PINP and ICTP were most indicative for SREs.
  
  
  CONCLUSIONS
  Bone markers are useful tools to predict and diagnose SRE in prostate cancer patients with bone metastases under receiving zoledronic acid therapy.
authors.affiliation: Department of Urology, Charité Hospital Berlin, University Medicine Berlin, Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Lein
authors.forename: Kurt
authors.initials: K
authors.lastname: Miller
authors.forename: Manfred
authors.initials: M
authors.lastname: Wirth
authors.forename: Lothar
authors.initials: L
authors.lastname: Weissbach
authors.forename: Christoph
authors.initials: C
authors.lastname: May
authors.forename: Katja
authors.initials: K
authors.lastname: Schmidt
authors.forename: Ulrike
authors.initials: U
authors.lastname: Haus
authors.forename: Mark
authors.initials: M
authors.lastname: Schrader
authors.forename: Klaus
authors.initials: K
authors.lastname: Jung
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000970:Antineoplastic Agents / Q000627:therapeutic use; D015415:Biomarkers / Q000378:metabolism; D050071:Bone Density Conservation Agents / Q000627:therapeutic use*; D001847:Bone Diseases / Q000188:drug therapy* / Q000209:etiology* / Q000517:prevention & control; D001842:Bone and Bones / Q000187:drug effects / Q000378:metabolism*; D024042:Collagen Type I; D004164:Diphosphonates / Q000627:therapeutic use*; D006801:Humans; D007093:Imidazoles / Q000627:therapeutic use*; D008297:Male; D015999:Multivariate Analysis; D010446:Peptide Fragments / Q000187:drug effects / Q000378:metabolism; D010455:Peptides; D011237:Predictive Value of Tests; D011347:Procollagen / Q000187:drug effects / Q000378:metabolism; D017430:Prostate-Specific Antigen / Q000187:drug effects / Q000378:metabolism; D011471:Prostatic Neoplasms / Q000150:complications* / Q000188:drug therapy / Q000473:pathology*; D012044:Regression Analysis; D000077211:Zoledronic Acid
chemical_list: D000970:Antineoplastic Agents; D015415:Biomarkers; D050071:Bone Density Conservation Agents; D024042:Collagen Type I; D004164:Diphosphonates; D007093:Imidazoles; D010446:Peptide Fragments; D010455:Peptides; D011347:Procollagen; C052929:collagen type I trimeric cross-linked peptide; D000077211:Zoledronic Acid; D017430:Prostate-Specific Antigen