title: Predictors of prostate cancer tissue acquisition by an undirected core bone marrow biopsy in metastatic castration-resistant prostate cancer--a Cancer and Leukemia Group B study.
abstract: OBJECTIVE
  Analyzing metastatic prostate cancer tissue is of considerable importance in evaluating new targeted agents, yet acquiring such tissue presents a challenge due to the predominance of bone metastases. We assessed factors predicting a successful tumor harvest from bone marrow biopsies (BMBx) in castration-resistant metastatic prostate cancer patients.
  
  
  METHODS
  Data from Cancer and Leukemia Group B study 9663 were reviewed. Bone marrow biopsies were obtained from 184 patients who underwent an office-based, unguided bone marrow biopsy of the posterior iliac crest.
  
  
  RESULTS
  Forty-seven of the 184 patients (25.5%) had a positive bone marrow biopsy. When considered in a multivariate logistic regression analysis, lower hemoglobin levels, higher alkaline phosphatase, and higher lactate dehydrogenase levels were associated with a higher likelihood of a positive BMBx. The median survival time was 11 months (95% confidence interval, 8.0-14) among patients with a positive BMBx compared with 23 months (95% confidence interval, 19-27) with a negative BMBx. The median time to progression and time to prostate-specific antigen progression-free survival were also significantly decreased among positive BMBx patients. No patients with a positive BMBx survived beyond 3 years, whereas 11 of the 137 patients with a negative BMBx survived beyond 5 years.
  
  
  CONCLUSIONS
  Using common laboratory values, a specific patient cohort can be defined from whom the yield of a nonguided BMBx would be high enough to justify this approach. For studies that require broader entry criteria, a more directed approach with image guidance is recommended.
authors.affiliation: Dana-Farber Cancer Institute, Boston, Massachusetts 02115, USA. rwross@partners.org
authors.forename: Robert W
authors.initials: RW
authors.lastname: Ross
authors.forename: Susan
authors.initials: S
authors.lastname: Halabi
authors.forename: San-San
authors.initials: SS
authors.lastname: Ou
authors.forename: Barur R
authors.initials: BR
authors.lastname: Rajeshkumar
authors.forename: Bruce A
authors.initials: BA
authors.lastname: Woda
authors.forename: Nicholas J
authors.initials: NJ
authors.lastname: Vogelzang
authors.forename: Eric J
authors.initials: EJ
authors.lastname: Small
authors.forename: Mary-Ellen
authors.initials: ME
authors.lastname: Taplin
authors.forename: Philip W
authors.initials: PW
authors.lastname: Kantoff
mesh_terms: D000368:Aged; D001706:Biopsy / Q000379:methods; D001853:Bone Marrow / Q000473:pathology*; D001856:Bone Marrow Examination / Q000379:methods; D001859:Bone Neoplasms / Q000556:secondary; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009919:Orchiectomy; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000473:pathology*; D012307:Risk Factors; D016019:Survival Analysis