title: Serum N-telopeptide and bone-specific alkaline phosphatase levels in patients with osteonecrosis of the jaw receiving bisphosphonates for bone metastases.
abstract: OBJECTIVE
  Oversuppression of bone turnover can be a critical factor in the pathogenesis of osteonecrosis of the jaw (ONJ). We investigated N-telopeptide of type I collagen (NTX) and bone-specific alkaline phosphatase (BAP) as potential predictors of ONJ onset.
  
  
  METHODS
  Patients with ONJ and available stored serum were identified retrospectively from the institutional databases. Four approximate points were examined: point of ONJ diagnosis and 12, 6, and 1 month before the diagnosis. NTX and BAP were measured using enzyme-linked immunosorbent assays and examined as possible predictors of ONJ.
  
  
  RESULTS
  From March 1998 to September 2009, we identified 122 patients with ONJ. Of these, 56 (46%) had one or more serum samples available. Overall, 55 patients (98%) received bisphosphonates. Using the exact dates, no obvious patterns in either NTX or BAP were noted. Similarly, using the ordinal points, no evidence of suppression of NTX or BAP over time was seen. The consecutive median values were as follows: The median NTX values were 8.0 nmol/L (range 3.8 to 32.9) at 12 months before ONJ; 9.5 nmol/L (range 4.7 to 42.7) at 6 months; 9.5 nmol/L (range 4.5 to 24.6) at 1 month, and 10.4 nmol/L (range 4.4 to 32.5) at the ONJ diagnosis. The median BAP values were BAP 18.0 U/L (range 7.0 to 74) at 12 months before ONJ; 18.0 U/L (range 4.0 to 134) at 6 months; 14.0 U/L (range 4.0 to 132) at 1 month, and 18.0 U/L (range 0.7 to 375) at the ONJ diagnosis. Only 2 patients (4%) had NTX and 17 (30%) had BAP below the normal range at the ONJ diagnosis.
  
  
  CONCLUSIONS
  In the present large retrospective study, no trends were seen in the NTX and BAP levels before the ONJ diagnosis.
authors.affiliation: Breast Cancer Medicine Service, Memorial Sloan-Kettering Cancer Center, New York, NY, USA. morrisp1@mskcc.org
authors.forename: Patrick G
authors.initials: PG
authors.lastname: Morris
authors.forename: Maurizio
authors.initials: M
authors.lastname: Fazio
authors.forename: Azeez
authors.initials: A
authors.lastname: Farooki
authors.forename: Cherry
authors.initials: C
authors.lastname: Estilo
authors.forename: Divya
authors.initials: D
authors.lastname: Mallam
authors.forename: Alison
authors.initials: A
authors.lastname: Conlin
authors.forename: Sujata
authors.initials: S
authors.lastname: Patil
authors.forename: Martin
authors.initials: M
authors.lastname: Fleisher
authors.forename: Serge
authors.initials: S
authors.lastname: Cremers
authors.forename: Joseph
authors.initials: J
authors.lastname: Huryn
authors.forename: Clifford A
authors.initials: CA
authors.lastname: Hudis
authors.forename: Monica N
authors.initials: MN
authors.lastname: Fornier
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000032:analysis*; D015415:Biomarkers / Q000097:blood; D059266:Bisphosphonate-Associated Osteonecrosis of the Jaw / Q000097:blood* / Q000201:enzymology; D050071:Bone Density Conservation Agents / Q000008:administration & dosage; D001859:Bone Neoplasms / Q000188:drug therapy / Q000556:secondary*; D001842:Bone and Bones / Q000201:enzymology*; D001943:Breast Neoplasms / Q000473:pathology; D024042:Collagen Type I / Q000097:blood*; D004164:Diphosphonates / Q000008:administration & dosage; D005260:Female; D005500:Follow-Up Studies; D005544:Forecasting; D006801:Humans; D008297:Male; D008875:Middle Aged; D010455:Peptides / Q000097:blood*; D011471:Prostatic Neoplasms / Q000473:pathology; D012189:Retrospective Studies; D013997:Time Factors
chemical_list: D015415:Biomarkers; D050071:Bone Density Conservation Agents; D024042:Collagen Type I; D004164:Diphosphonates; D010455:Peptides; C052929:collagen type I trimeric cross-linked peptide; D000469:Alkaline Phosphatase