title: Larger maximum tumor diameter at radical prostatectomy is associated with increased biochemical failure, metastasis, and death from prostate cancer after salvage radiation for prostate cancer.
abstract: OBJECTIVE
  To investigate the maximum tumor diameter (MTD) of the dominant prostate cancer nodule in the radical prostatectomy specimen as a prognostic factor for outcome in patients treated with salvage external beam radiation therapy (SRT) for a rising prostate-specific antigen (PSA) value after radical prostatectomy.
  
  
  METHODS
  From an institutional cohort of 575 patients treated with SRT, data on MTD were retrospectively collected. The impact of MTD on biochemical failure (BF), metastasis, and prostate cancer-specific mortality (PCSM) was assessed on univariate and multivariate analysis using Kaplan-Meier and Cox proportional hazards models.
  
  
  RESULTS
  In the 173 patients with MTD data available, median follow-up was 77 months (interquartile range, 47-104 months) after SRT, and median MTD was 18 mm (interquartile range, 13-22 mm). Increasing MTD correlated with increasing pT stage, Gleason score, presence of seminal vesicle invasion, and lymph node invasion. Receiver operating characteristic curve analysis identified MTD of >14 mm to be the optimal cut-point. On univariate analysis, MTD >14 mm was associated with an increased risk of BF (P=.02, hazard ratio [HR] 1.8, 95% confidence interval [CI] 1.2-2.8), metastasis (P=.002, HR 4.0, 95% CI 2.1-7.5), and PCSM (P=.02, HR 8.0, 95% CI 2.9-21.8). On multivariate analysis MTD >14 mm remained associated with increased BF (P=.02, HR 1.9, 95% CI 1.1-3.2), metastasis (P=.02, HR 3.4, 95% CI 1.2-9.2), and PCSM (P=.05, HR 9.7, 95% CI 1.0-92.4), independent of extracapsular extension, seminal vesicle invasion, positive surgical margins, pre-RT PSA value, Gleason score, and pre-RT PSA doubling time.
  
  
  CONCLUSIONS
  For patients treated with SRT for a rising PSA value after prostatectomy, MTD at time of radical prostatectomy is independently associated with BF, metastasis, and PCSM. Maximum tumor diameter should be incorporated into clinical decision making and future clinical risk assessment tools for those patients receiving SRT.
authors.affiliation: Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan, USA.
authors.forename: Skyler B
authors.initials: SB
authors.lastname: Johnson
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hamstra
authors.forename: William C
authors.initials: WC
authors.lastname: Jackson
authors.forename: Jessica
authors.initials: J
authors.lastname: Zhou
authors.forename: Benjamin
authors.initials: B
authors.lastname: Foster
authors.forename: Corey
authors.initials: C
authors.lastname: Foster
authors.forename: Yeohan
authors.initials: Y
authors.lastname: Song
authors.forename: Darren
authors.initials: D
authors.lastname: Li
authors.forename: Ganesh S
authors.initials: GS
authors.lastname: Palapattu
authors.forename: Lakshmi
authors.initials: L
authors.lastname: Kunju
authors.forename: Rohit
authors.initials: R
authors.lastname: Mehra
authors.forename: Howard
authors.initials: H
authors.lastname: Sandler
authors.forename: Felix Y
authors.initials: FY
authors.lastname: Feng
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D006801:Humans; D008198:Lymph Nodes / Q000473:pathology; D008297:Male; D008875:Middle Aged; D060787:Neoplasm Grading; D009361:Neoplasm Invasiveness; D009364:Neoplasm Recurrence, Local / Q000401:mortality / Q000532:radiotherapy; D009367:Neoplasm Staging; D011379:Prognosis; D017430:Prostate-Specific Antigen / Q000097:blood*; D011468:Prostatectomy / Q000379:methods* / Q000401:mortality; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012372:ROC Curve; D012189:Retrospective Studies; D016879:Salvage Therapy / Q000379:methods* / Q000401:mortality; D012669:Seminal Vesicles / Q000473:pathology; D047368:Tumor Burden
chemical_list: D017430:Prostate-Specific Antigen