title: Prognostic value of biochemical variables for survival after surgery for metastatic bone disease of the extremities.
abstract: OBJECTIVE
  Prediction of survival in patients having surgery for metastatic bone disease in the extremities (MBDex) has been of interest in more than two decades. Hitherto no consensus on the value of biochemical variables has been achieved. Our purpose was (1) to investigate if standard biochemical variables have independent prognostic value for survival after surgery for MBDex and (2) to identify optimal prognostic cut off values for survival of biochemical variables.
  
  
  METHODS
  In a consecutive cohort of 270 patients having surgery for MBDex, we measured preoperative biochemical variables: hemoglobin, alkaline phosphatase, C-reactive protein and absolute, neutrophil and lymphocyte count. ROC curve analyses were performed to identify optimal cut off levels. Independent prognostic factors for variables were addressed with multiple Cox regression analyses.
  
  
  RESULTS
  Optimal cut off levels were identified as: hemoglobin 7.45 mmol/L, absolute lymphocyte count 8.5 × 109/L, neutrophil 5.68 × 109/L, lymphocyte 1.37 × 109/L, C-reactive protein 22.5 mg/L, and alkaline phosphatase 129 U/L. Regression analyses found alkaline phosphatase (HR 2.49) and neutrophil count (HR 2.49) to be independent prognostic factors.
  
  
  CONCLUSIONS
  We found neutrophil count and alkaline phosphatase to be independent prognostic variables in predicting survival in patients after surgery for MBDex.
authors.affiliation: Musculoskeletal Tumor Section, Department of Orthopedic Surgery, Rigshospitalet, University of Copenhagen, Copenhagen Ø, Denmark.
authors.forename: Michala Skovlund
authors.initials: MS
authors.lastname: Sørensen
authors.affiliation: Musculoskeletal Tumor Section, Department of Orthopedic Surgery, Rigshospitalet, University of Copenhagen, Copenhagen Ø, Denmark.
authors.forename: Thea Bechman
authors.initials: TB
authors.lastname: Hovgaard
authors.affiliation: Pediatric Orthopedic Section, University of Copenhagen, Copenhagen Ø, Denmark.
authors.forename: Klaus
authors.initials: K
authors.lastname: Hindsø
authors.affiliation: Musculoskeletal Tumor Section, Department of Orthopedic Surgery, Rigshospitalet, University of Copenhagen, Copenhagen Ø, Denmark.
authors.forename: Michael Mørk
authors.initials: MM
authors.lastname: Petersen
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000469:Alkaline Phosphatase / Q000097:blood; D015415:Biomarkers / Q000097:blood; D001859:Bone Neoplasms / Q000401:mortality* / Q000556:secondary / Q000601:surgery; D002097:C-Reactive Protein / Q000032:analysis; D015331:Cohort Studies; D005121:Extremities / Q000473:pathology / Q000601:surgery; D005260:Female; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D007958:Leukocyte Count; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000378:metabolism; D011379:Prognosis; D012044:Regression Analysis; D055815:Young Adult
chemical_list: D015415:Biomarkers; D006454:Hemoglobins; D002097:C-Reactive Protein; D000469:Alkaline Phosphatase
keywords: biochemical variables; joint replacement surgery; metastatic bone disease; orthopedic oncology; prognostication; survival