title: The presence of primary circulating prostate cells is associated with upgrading and upstaging in patients eligible for active surveillance.
abstract: Active surveillance (AS) is a considered treatment option for men with low or very low-risk prostate cancer. However, on repeat biopsy some 25% were upgraded and recommended for active treatment. We compare the presence or absence of primary circulating prostate cells (CPCs) with the clinical pathological findings after radical prostatectomy in men fulfilling the criteria for active surveillance and the risk of reclassification for active observation (AO).
  
  
  METHODS
  A single centre observational study was done involving 102 men who fulfilled the Epstein criteria for AS and underwent radical prostatectomy as mono-therapy for prostate cancer. The patients were classified according to the presence or absence of CPCs detected immediately before the prostate biopsy. Mononuclear cells were obtained by differential gel centrifugation of 8 mL of venous blood and CPCs identified using immunocytochemistry with anti-PSA and anti-P504S. A positive CPC test was defined as at least 1 PSA (+), P504S (+) cell detected/blood sample. The surgical specimen was analysed for Gleason score and pathological stage.
  
  
  RESULTS
  A total of 25 out of 102 (24.5%) men were upgraded based on the pathological findings of the surgical specimen. Among which 45 (44%) men were positive for CPCs. They were younger, 63.9 versus 68.1 years (p = 0.0148), had a lower frequency of pT2 or lower disease (64.4% versus 91.2% p <0.001), higher median Gleason scores (6 versus 5 p < 0.001) in both the biopsy and surgical specimens, and a higher frequency of upgrading 44% versus 9% (p < 0.001).
  
  
  CONCLUSIONS
  In men fulfilling the criteria for AS, the presence of primary CPCs suggests a high risk for disease upgrade and therefore these men may not be ideal for observational therapy. Further studies with a larger population are warranted.
authors.affiliation: Hospital Carabineros of Chile, Nunoa, 7770199 Santiago, Chile; Faculty of Medicine, University Finis Terrae, Providencia, 7501015 Santiago, Chile.
authors.forename: Nigel P
authors.initials: NP
authors.lastname: Murray
authors.affiliation: Faculty of Medicine, University Diego Portales, Manuel Rodrıguez Sur 415, 8370179 Santiago, Chile; Hospital DIPRECA, La Reina, Santiago, Chile.
authors.forename: Eduardo
authors.initials: E
authors.lastname: Reyes
authors.affiliation: Hospital Carabineros of Chile, Nunoa, 7770199 Santiago, Chile.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Fuentealba
authors.affiliation: Faculty of Medicine, University Finis Terrae, Providencia, 7501015 Santiago, Chile.
authors.forename: Socrates
authors.initials: S
authors.lastname: Aedo
authors.affiliation: Hospital Carabineros of Chile, Nunoa, 7770199 Santiago, Chile.
authors.forename: Omar
authors.initials: O
authors.lastname: Jacob
keywords: active surveillance; circulating prostate cells; prostate cancer