title: Perineural invasion is a marker for pathologically advanced disease in localized prostate cancer.
abstract: OBJECTIVE
  To determine if perineural invasion (PNI) should be included in addition to prostate-specific antigen (PSA), biopsy Gleason score, and clinical T-stage for risk-stratification of patients with localized prostate cancer.
  
  
  METHODS
  We analyzed prostatectomy findings for 1550 patients, from a prospectively collected institutional database, to determine whether PNI was a significant predictor for upgrading of Gleason score or pathologic T3 disease after patients were stratified into low-, intermediate-, and high-risk groups (on the basis of PSA, biopsy Gleason score, and clinical T-stage).
  
  
  RESULTS
  For the overall population, PNI was associated with a significantly increased frequency of upgrading and of pathologic T3 disease. After stratification, PNI was still associated with significantly increased odds of pathologic T3 disease within each risk group. In particular, for low-risk patients, there was a markedly increased risk of extraprostatic extension (23% vs. 7%), comparable to that of intermediate-risk patients. Among high-risk patients, PNI was associated with an increased risk of seminal vesicle invasion and lymph node involvement. Furthermore, over 80% of high-risk patients with PNI were noted to have an indication for postoperative radiation.
  
  
  CONCLUSIONS
  Perineural invasion may be useful for risk-stratification of prostate cancer. Our data suggest that low-risk patients with PNI on biopsy may benefit from treatment typically reserved for those with intermediate-risk disease. In addition, men with high-risk disease and PNI, who are contemplating surgery, should be informed of the high likelihood of having an indication for postoperative radiation therapy.
authors.affiliation: Department of Radiation Oncology, University of Michigan, 1500 E. Medical Center Drive, Ann Arbor, MI 48109, USA. irwinlee@med.umich.edu
authors.forename: Irwin H
authors.initials: IH
authors.lastname: Lee
authors.forename: Rebecca
authors.initials: R
authors.lastname: Roberts
authors.forename: Rajal B
authors.initials: RB
authors.lastname: Shah
authors.forename: Kirk J
authors.initials: KJ
authors.lastname: Wojno
authors.forename: John T
authors.initials: JT
authors.lastname: Wei
authors.forename: Howard M
authors.initials: HM
authors.lastname: Sandler
mesh_terms: D006801:Humans; D008207:Lymphatic Metastasis; D008297:Male; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods*; D011446:Prospective Studies; D011467:Prostate / Q000294:innervation / Q000473:pathology*; D017430:Prostate-Specific Antigen / Q000097:blood; D011471:Prostatic Neoplasms / Q000097:blood / Q000473:pathology*; D012669:Seminal Vesicles / Q000473:pathology
chemical_list: D017430:Prostate-Specific Antigen