title: Lifelong yearly prostate specific antigen surveillance is not necessary for low risk prostate cancer treated with radical prostatectomy.
abstract: OBJECTIVE
  Many patients undergoing radical prostatectomy in the prostate specific antigen era have a low risk of recurrence. Aggressive postoperative prostate specific antigen surveillance is costly and anxiety provoking. In this study we investigate the need for yearly prostate specific antigen measurements in patients with surgically treated low risk prostate cancer.
  
  
  METHODS
  We identified 2,219 patients who underwent radical prostatectomy between 1994 and 2004 for low risk localized prostate cancer. Low risk was defined as prostate specific antigen less than 10 ng/ml, pathological stage pT2c or less, Gleason score 6 or less, negative lymph nodes and negative surgical margins. Patients who underwent neoadjuvant or adjuvant therapy were excluded from analysis. Biochemical failure was defined as a prostate specific antigen greater than 0.4 ng/ml and prostate specific antigen values less than 0.15 ng/ml were considered undetectable. Biochemical failure rates were calculated according to the duration of the prostate specific antigen-free period after radical prostatectomy.
  
  
  RESULTS
  A total of 142 (6.4%) patients experienced biochemical failure during the course of the study. The risk of biochemical failure decreased with increasing duration of the prostate specific antigen-free interval. For example 1, 3 and 5-year biochemical failure rates calculated at surgery were 1.8%, 4.2% and 6.3%, respectively. For patients with undetectable prostate specific antigen measurements 5 years after surgery the 1, 3 and 5-year biochemical failure rates were 0.0%, 0.7% and 1.3%, respectively. In addition, 1-year biochemical failure rates were 0.2%, 0.4%, 0.0% and 0.0% after a prostate specific antigen-free period of 1, 3, 5 and 10 years, respectively.
  
  
  CONCLUSIONS
  The risk of biochemical failure is inversely proportional to the duration of the prostate specific antigen-free interval after radical prostatectomy in low risk patients. Biochemical failure 1 year after an undetectable prostate specific antigen is uncommon, especially after a prostate specific antigen-free period of 3 years. These data suggest that annual prostate specific antigen measurements are unnecessary, especially after a prostate specific antigen-free interval of 3 years. Prostate specific antigen measurements every 2 years should capture the majority of low risk patients who experience progression.
authors.affiliation: Department of Urology, Mayo Medical School and Mayo Clinic, Rochester, Minnesota 55905, USA. tollefson.matthew@mayo.edu
authors.forename: Matthew K
authors.initials: MK
authors.lastname: Tollefson
authors.forename: Michael L
authors.initials: ML
authors.lastname: Blute
authors.forename: Laureano J
authors.initials: LJ
authors.lastname: Rangel
authors.forename: R Jeffrey
authors.initials: RJ
authors.lastname: Karnes
authors.forename: Igor
authors.initials: I
authors.lastname: Frank
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000097:blood* / Q000601:surgery*; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors
chemical_list: D017430:Prostate-Specific Antigen