title: Imaging, procedural and clinical variables associated with tumor yield on bone biopsy in metastatic castration-resistant prostate cancer.
abstract: BACKGROUND
  Understanding the mechanisms driving disease progression is fundamental to identifying new therapeutic targets for the treatment of men with metastatic castration-resistant prostate cancer (mCRPC). Owing to the prevalence of bone metastases in mCRPC, obtaining sufficient tumor tissue for analysis has historically been a challenge. In this exploratory analysis, we evaluated imaging, procedural and clinical variables associated with tumor yield on image-guided bone biopsy in men with mCRPC.
  
  
  METHODS
  Clinical data were collected prospectively from men with mCRPC enrolled on a phase II trial with serial metastasis biopsies performed according to standard clinical protocol. Imaging was retrospectively reviewed. We evaluated the percent positive biopsy cores (PPC), calculated as the number of positive cores divided by the total number of cores collected per biopsy.
  
  
  RESULTS
  Twenty-nine men had 39 bone biopsies. Seventy-seven percent of bone biopsies had at least one positive biopsy core. We determined that lesion size and distance from the skin to the lesion edge correlated with tumor yield on biopsy (median PPC 75% versus 42% for lesions >8.8 cm(3) versus ⩽ 8.8 cm(3), respectively, P=0.05; median PPC 33% versus 71% for distance ⩾ 6.1 versus <6.1 cm, respectively, P = 0.02). There was a trend towards increased tumor yield in patients with increased uptake on radionuclide bone scan, higher calcium levels and shorter duration of osteoclast-targeting therapy, although this was not statistically significant. Ten men had 14 soft tissue biopsies. All soft tissue biopsies had at least one positive biopsy core.
  
  
  CONCLUSIONS
  This exploratory analysis suggests that there are imaging, procedural and clinical variables that have an impact on image-guided bone biopsy yield. In order to maximize harvest of prostate cancer tissue, we have incorporated a prospective analysis of the metrics described here as part of a multi-institutional project aiming to use the molecular characterization of mCRPC tumors to direct individual therapy.
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: R R
authors.initials: RR
authors.lastname: McKay
authors.affiliation: 1] Sunnybrook Health Sciences Centre, University of Toronto, Toronto, Ontario, Canada [2] Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: K A
authors.initials: KA
authors.lastname: Zukotynski
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: L
authors.initials: L
authors.lastname: Werner
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: O
authors.initials: O
authors.lastname: Voznesensky
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: J S
authors.initials: JS
authors.lastname: Wu
authors.affiliation: 1] Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA [2] Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: S E
authors.initials: SE
authors.lastname: Smith
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: Z
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: K
authors.initials: K
authors.lastname: Melnick
authors.affiliation: Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: X
authors.initials: X
authors.lastname: Yuan
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: P W
authors.initials: PW
authors.lastname: Kantoff
authors.affiliation: Fred Hutchinson Cancer Research Center, University of Washington, Seattle, WA, USA.
authors.forename: B
authors.initials: B
authors.lastname: Montgomery
authors.affiliation: Beth Israel Deaconess Medical Center, Boston, MA, USA.
authors.forename: S P
authors.initials: SP
authors.lastname: Balk
authors.affiliation: Lank Center for Genitourinary Oncology, Dana-Farber Cancer Institute, Boston, MA, USA.
authors.forename: M-E
authors.initials: ME
authors.lastname: Taplin
mesh_terms: D000368:Aged; D000726:Androgen Antagonists / Q000627:therapeutic use; D000736:Androstenes / Q000008:administration & dosage; D018931:Antineoplastic Agents, Hormonal / Q000627:therapeutic use; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use; D001378:Azasteroids / Q000008:administration & dosage; D001706:Biopsy / Q000379:methods*; D001859:Bone Neoplasms / Q000000981:diagnostic imaging* / Q000556:secondary*; D019008:Drug Resistance, Neoplasm; D000068538:Dutasteride; D006801:Humans; D008297:Male; D008875:Middle Aged; D064129:Prostatic Neoplasms, Castration-Resistant / Q000000981:diagnostic imaging / Q000473:pathology*; D015641:Radiography, Interventional / Q000379:methods*; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D025321:Surgery, Computer-Assisted / Q000379:methods; D013669:Technetium Tc 99m Medronate
chemical_list: D000726:Androgen Antagonists; D000736:Androstenes; D018931:Antineoplastic Agents, Hormonal; D001378:Azasteroids; D019275:Radiopharmaceuticals; C089740:abiraterone; D000068538:Dutasteride; D013669:Technetium Tc 99m Medronate
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