title: Tumor volume as a predictor of adverse pathologic features and biochemical recurrence (BCR) in radical prostatectomy specimens: a tale of two methods.
abstract: OBJECTIVE
  The prognostic value of tumor volume in predicting biochemical recurrence after prostatectomy has been debated. Our aim in this study was to (a) evaluate tumor volume as an independent predictor of adverse pathologic outcomes and BCR and (b) determine the effect of two different methods of tumor volume estimation.
  
  
  METHODS
  We reviewed the charts of 3,087 patients who underwent radical prostatectomy at Vanderbilt University Medical Center between 2000 and 2008; of which 1,747 patients had data sufficient for analysis. Prostate specimens were processed as whole mount between 2000 and 2003 and then via systematic sampling from 2003 to 2008, with tumor volume measured by planimetry in the whole-mount group and tumor volume estimated by percent tumor involvement in the systematic sampling group.
  
  
  RESULTS
  Tumor volume estimates were higher with SS than with WM. There were significant associations between larger tumor volume and adverse pathological outcomes, regardless of pathologic method (all with P<0.001). Controlling for other pathologic parameters, tumor volume was an independent predictor of PGS, EPE, and SM in logistic regression models (P<0.001 for TV in all models). Tumor volume was demonstrated to be an independent predictor of BCR in the WM group (1.06, 95% CI 1.01-1.11, P=0.013), though tumor volume was not a significant predictor of BCR in the SS group.
  
  
  CONCLUSIONS
  Though the prognostic value of tumor volume is debated, our data demonstrate that tumor volume, when calculated via planimetry on whole-mount pathologic sectioning, is a significant predictor of biochemical recurrence after prostatectomy.
authors.affiliation: Department of Urologic Surgery, Vanderbilt University Medical Center, 2525 West End Ave, Suite 600, Nashville, TN, 37203, USA.
authors.forename: Ian M
authors.initials: IM
authors.lastname: Thompson
authors.forename: Shady
authors.initials: S
authors.lastname: Salem
authors.forename: Sam S
authors.initials: SS
authors.lastname: Chang
authors.forename: Peter E
authors.initials: PE
authors.lastname: Clark
authors.forename: Rodney
authors.initials: R
authors.lastname: Davis
authors.forename: S Duke
authors.initials: SD
authors.lastname: Herrell
authors.forename: Yakup
authors.initials: Y
authors.lastname: Kordan
authors.forename: Roxelyn
authors.initials: R
authors.lastname: Baumgartner
authors.forename: Sharon
authors.initials: S
authors.lastname: Phillips
authors.forename: Joseph A
authors.initials: JA
authors.lastname: Smith
authors.forename: Michael S
authors.initials: MS
authors.lastname: Cookson
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Barocas
mesh_terms: D000368:Aged; D006801:Humans; D015994:Incidence; D008297:Male; D008867:Microtomy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000175:diagnosis* / Q000453:epidemiology*; D011237:Predictive Value of Tests; D011379:Prognosis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology* / Q000601:surgery*; D012189:Retrospective Studies; D015983:Selection Bias; D047368:Tumor Burden