title: Comparison of observed biochemical recurrence-free survival in patients with low PSA values undergoing radical prostatectomy and predictions of preoperative nomogram.
abstract: OBJECTIVE
  A preoperative nomogram is an effective tool for assessing the risk of disease progression after radical prostatectomy for localized prostate cancer. To better understand the performance of nomograms for patients with a low prostate-specific antigen (PSA) level, we examined whether patients with a PSA level <2.5 ng/mL had outcomes different than predicted by a validated preoperative nomogram.
  
  
  METHODS
  A cohort of 6130 patients from 2 referral centers was analyzed. Kaplan-Meier methods were used to estimate the recurrence-free probabilities stratified by PSA group (<2.5 vs >or=2.5 ng/mL). Cox proportional hazards regression analysis was used to evaluate whether the PSA grouping was associated with biochemical recurrence, controlling for preoperative nomogram probability.
  
  
  RESULTS
  Of 6130 patients, 399 (6.5%) had a PSA level <2.5 ng/mL. Patients with a PSA level of <or=0.5 ng/mL had a high rate of nonorgan-confined disease (33% vs 15% for PSA levels of 0.6-2.5 ng/mL). The median follow-up for recurrence-free patients was 2.4 years, and 10 patients with a PSA level of <2.5 ng/mL and 597 patients with a PSA level >2.5 ng/mL developed recurrence (total 607/6130). With adjustment for the preoperative nomogram probability, no significant difference was found in recurrence by PSA grouping (hazard ratio 0.78 for PSA <2.5 vs >or=2.5 ng/mL; 95% confidence interval 0.42-1.48; P = .5).
  
  
  CONCLUSIONS
  Patients with a low PSA comprise a small proportion of those treated, and most have palpable disease. Patients with especially low PSA values (<or=0.5 ng/mL) have a high rate of nonorgan-confined disease. We saw no evidence that patients with low PSA levels have worse outcomes, after the stage and grade were taken into account.
authors.affiliation: Division of Urology, Memorial Sloan-Kettering Cancer Center, New York, New York 10021, USA.
authors.forename: Ryan K
authors.initials: RK
authors.lastname: Berglund
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Stephenson
authors.forename: Angel M
authors.initials: AM
authors.lastname: Cronin
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Vickers
authors.forename: James A
authors.initials: JA
authors.lastname: Eastham
authors.forename: Eric A
authors.initials: EA
authors.lastname: Klein
authors.forename: Bertrand D
authors.initials: BD
authors.lastname: Guillonneau
mesh_terms: D000368:Aged; D001707:Biopsy, Needle; D015331:Cohort Studies; D018572:Disease-Free Survival; D005500:Follow-Up Studies; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000473:pathology; D009367:Neoplasm Staging; D049451:Nomograms; D011300:Preoperative Care / Q000379:methods; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000379:methods*; D011471:Prostatic Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery*; D012189:Retrospective Studies; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D015996:Survival Rate; D016896:Treatment Outcome
chemical_list: D017430:Prostate-Specific Antigen