title: Prognostic significance of circulating tumor cells in patients with hormone refractory prostate cancer.
abstract: OBJECTIVE
  Using the CellSearch System we evaluated whether circulating tumor cells predict survival in patients with hormone refractory prostate cancer.
  
  
  METHODS
  Circulating tumor cells were counted with the CellSearch System in whole blood. This system was developed using epithelial cell adhesion prostate cancer antibody based, immunomagnetic capture and automated staining methodology. Blood samples from 64 patients with hormone refractory prostate cancer were analyzed.
  
  
  RESULTS
  A threshold of 5 or more circulating tumor cells per 7.5 ml blood was used to evaluate the ability of circulating tumor cells to predict survival. Patient charts were retrospectively examined to determine median overall survival, which was 4 to 27 months (mean +/- SD 14.3 +/- 4.2, median 12.1). Of the 64 patients 32 (50%) had 5 or more circulating tumor cells with a median overall survival of 13.0 months compared with 20.0 months in patients with fewer than 5 (p <0.001). Circulating tumor cells and prostate specific antigen doubling time were significant parameters predicting overall survival on univariate and multivariate analyses. Overall survival in cases that converted from increased to nonincreased circulating tumor cell levels was longer than in cases that converted from nonincreased to increased levels after initiating the circulating tumor cell assay (p = 0.026).
  
  
  CONCLUSIONS
  In this study 5 or more circulating tumor cells in 7.5 ml blood was associated with survival in patients with hormone refractory prostate cancer. Circulating tumor cells may be an independent predictor of overall survival in patients with hormone refractory prostate cancer but they may also complement prostate specific antigen.
authors.affiliation: Department of Urology, University of Kyorin, Tokyo, Japan.
authors.forename: Takatsugu
authors.initials: T
authors.lastname: Okegawa
authors.forename: Kikuo
authors.initials: K
authors.lastname: Nutahara
authors.forename: Eiji
authors.initials: E
authors.lastname: Higashihara
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000726:Androgen Antagonists / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009360:Neoplastic Cells, Circulating; D009919:Orchiectomy; D011379:Prognosis; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000473:pathology* / Q000628:therapy; D012189:Retrospective Studies; D015996:Survival Rate; D017211:Treatment Failure
chemical_list: D000726:Androgen Antagonists