title: How much does Gleason grade of follow-up biopsy differ from that of initial biopsy in untreated, Gleason score 4-7, clinically localized prostate cancer?
abstract: OBJECTIVE
  To compare histologic grades between an initial biopsy and a follow-up biopsy in untreated, Gleason score (GS) 4-7, clinically localized prostate cancer.
  
  
  METHODS
  In a prospective single-arm cohort study, clinically localized, GS 4-7, prostate cancer was managed with active surveillance alone, provided that a pre-defined definition of disease progression was not met. One hundred five (63%) of a total of 168 eligible patients underwent a follow-up prostate biopsy during surveillance. Median time to a follow-up biopsy was 22 months (range: 7-81). Histologic grades between these two biopsies were compared to evaluate the extent of histologic grade change.
  
  
  RESULTS
  On the follow-up biopsy, GS was unchanged in 33 patients (31%), upgraded in 37 (35%), and downgraded in 34 (32%). Eleven (10%) had upgrading by 2 Gleason points or more. Eight (8%) had upgrading to GS 8 (none to GS 9 or 10); of these, six were among those with upgrading by 2 Gleason points or more. Twenty-seven (26%) had no malignancy on the follow-up biopsy. Negative follow-up biopsy was more prevalent in patients with a small volume of malignancy in the initial biopsy and a low baseline PSA.
  
  
  CONCLUSIONS
  No consistent change in histologic grade was observed on the follow-up biopsy at a median of 22 months in untreated, GS 4-7, clinically localized prostate cancer. Upgrading to GS > or =8 or by 2 Gleason points or more was relatively uncommon.
authors.affiliation: Department of Radiation Oncology, Mayo Clinic, Rochester, MN 55905, USA.
authors.forename: R
authors.initials: R
authors.lastname: Choo
authors.forename: C
authors.initials: C
authors.lastname: Danjoux
authors.forename: G
authors.initials: G
authors.lastname: Morton
authors.forename: E
authors.initials: E
authors.lastname: Szumacher
authors.forename: L
authors.initials: L
authors.lastname: Sugar
authors.forename: S
authors.initials: S
authors.lastname: Gardner
authors.forename: M
authors.initials: M
authors.lastname: Kim
authors.forename: C M
authors.initials: CM
authors.lastname: Choo
authors.forename: L
authors.initials: L
authors.lastname: Klotz
mesh_terms: D000230:Adenocarcinoma / Q000097:blood / Q000145:classification / Q000175:diagnosis*; D000368:Aged; D000369:Aged, 80 and over; D001706:Biopsy; D018450:Disease Progression; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D008991:Monitoring, Physiologic; D009367:Neoplasm Staging; D011379:Prognosis; D011446:Prospective Studies; D011467:Prostate / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000145:classification / Q000175:diagnosis*