title: Extended followup and risk factors for disease reclassification in a large active surveillance cohort for localized prostate cancer.
abstract: OBJECTIVE
  Active surveillance to manage prostate cancer provides an alternative to immediate treatment in men with low risk prostate cancer. We report updated outcomes from a long-standing active surveillance cohort and factors associated with reclassification.
  
  
  METHODS
  We retrospectively reviewed data on all men enrolled in the active surveillance cohort at our institution with at least 6 months of followup between 1990 and 2013. Surveillance consisted of quarterly prostate specific antigen testing, repeat imaging with transrectal ultrasound at provider discretion and periodic repeat prostate biopsies. Factors associated with repeat biopsy reclassification and local treatment were determined by multivariate Cox proportional hazards regression. We also analyzed the association of prostate specific antigen density and outcomes stratified by prostate size.
  
  
  RESULTS
  A total of 810 men who consented to participate in the research cohort were followed on active surveillance for a median of 60 months. Of these men 556 (69%) met strict criteria for active surveillance. Five-year overall survival was 98%, treatment-free survival was 60% and biopsy reclassification-free survival was 40%. There were no prostate cancer related deaths. On multivariate analysis prostate specific antigen density was positively associated with the risk of biopsy reclassification and treatment while the number of biopsies and time between biopsies were inversely associated with the 2 outcomes (each p <0.01). When stratified by prostate volume, prostate specific antigen density remained significantly associated with biopsy reclassification for all strata but prostate specific antigen density was only significantly associated with treatment in men with a smaller prostate.
  
  
  CONCLUSIONS
  Significant prostate cancer related morbidity and mortality remained rare at intermediate followup. Prostate specific antigen density was independently associated with biopsy reclassification and treatment while on active surveillance.
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California. Electronic address: weltyc@urology.ucsf.edu.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Welty
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Janet E
authors.initials: JE
authors.lastname: Cowan
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Hao
authors.initials: H
authors.lastname: Nguyen
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Katsuto
authors.initials: K
authors.lastname: Shinohara
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Nannette
authors.initials: N
authors.lastname: Perez
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Kirsten L
authors.initials: KL
authors.lastname: Greene
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: June M
authors.initials: JM
authors.lastname: Chan
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Maxwell V
authors.initials: MV
authors.lastname: Meng
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Jeffry P
authors.initials: JP
authors.lastname: Simko
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Cooperberg
authors.affiliation: Department of Urology, University of California-San Francisco Helen Diller Family Comprehensive Cancer Center, University of California-San Francisco, San Francisco, California.
authors.forename: Peter R
authors.initials: PR
authors.lastname: Carroll
mesh_terms: D001706:Biopsy; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011467:Prostate / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000145:classification* / Q000473:pathology*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D057832:Watchful Waiting
chemical_list: D017430:Prostate-Specific Antigen
keywords: biopsy; disease progression; outcome assessment; prostate-specific antigen; prostatic neoplasms