title: Perineural invasion predicts increased recurrence, metastasis, and death from prostate cancer following treatment with dose-escalated radiation therapy.
abstract: OBJECTIVE
  To assess the prognostic value of perineural invasion (PNI) for patients treated with dose-escalated external-beam radiation therapy for prostate cancer.
  
  
  METHODS
  Outcomes were analyzed for 651 men treated for prostate cancer with EBRT to a minimum dose ≥75 Gy. We assessed the impact of PNI as well as pretreatment and treatment-related factors on freedom from biochemical failure (FFBF), freedom from metastasis (FFM), cause-specific survival (CSS), and overall survival.
  
  
  RESULTS
  PNI was present in 34% of specimens at biopsy and was significantly associated with higher Gleason score (GS), T stage, and prostate-specific antigen level. On univariate and multivariate analysis, the presence of PNI was associated with worse FFBF (hazard ratio = 1.7, p <0.006), FFM (hazard ratio = 1.8, p <0.03), and CSS (HR = 1.4, p <0.05) compared with absence of PNI; there was no difference in overall survival. Seven-year rates of FFBF, FFM, and CCS were 64% vs. 80%, 84% vs. 92%, and 91% vs. 95% for those patients with and without PNI, respectively. On recursive partitioning analysis, PNI predicted for worse FFM and CSS in patients with GS 8-10, with FFM of 67% vs. 89% (p <0.02), and CSS of 69% vs. 91%, (p <0.04) at 7 years for those with and without PNI, respectively.
  
  
  CONCLUSIONS
  The presence of PNI in the prostate biopsy predicts worse clinical outcome for patients treated with dose-escalated external-beam radiation therapy. Particularly in patients with GS 8-10 disease, the presence of PNI suggests an increased risk of metastasis and prostate cancer death.
authors.affiliation: The University of Michigan Medical Center, Ann Arbor, MI 48109-5010, USA.
authors.forename: Felix Y
authors.initials: FY
authors.lastname: Feng
authors.forename: Yushen
authors.initials: Y
authors.lastname: Qian
authors.forename: Matthew H
authors.initials: MH
authors.lastname: Stenmark
authors.forename: Schuyler
authors.initials: S
authors.lastname: Halverson
authors.forename: Kevin
authors.initials: K
authors.lastname: Blas
authors.forename: Sean
authors.initials: S
authors.lastname: Vance
authors.forename: Howard M
authors.initials: HM
authors.lastname: Sandler
authors.forename: Daniel A
authors.initials: DA
authors.lastname: Hamstra
mesh_terms: D000368:Aged; D000465:Algorithms; D000704:Analysis of Variance; D001706:Biopsy; D006801:Humans; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D009361:Neoplasm Invasiveness / Q000473:pathology; D009364:Neoplasm Recurrence, Local; D011467:Prostate / Q000293:injuries / Q000473:pathology; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy; D011878:Radiotherapy / Q000379:methods; D011879:Radiotherapy Dosage; D016019:Survival Analysis
chemical_list: D017430:Prostate-Specific Antigen