title: Detection of occult lymph node metastases in locally advanced node-negative prostate cancer.
abstract: OBJECTIVE
  The purpose of this study was to determine the incidence and clinical significance of occult metastases in the lymph nodes of patients with prostate cancer originally considered node negative by routine histologic evaluation.
  
  
  METHODS
  Two hundred seventy four patients with pT3 prostate carcinoma treated by radical prostatectomy and bilateral lymph node dissection were included in this study. One hundred eighty patients were staged node negative (N0), while 94 patients were lymph node positive (N+), based on routine histologic evaluation. All lymph nodes from the 180 N0 patients were evaluated for occult metastases by immunohistochemistry using antibodies to cytokeratins and, if positive, prostate-specific antigen. Recurrence and overall survival were compared among patients with occult tumor cells (OLN+), with patients whose lymph nodes remained negative (OLN-), and with the 94 N+ patients.
  
  
  RESULTS
  A total of 3,914 lymph nodes were evaluated from 180 N0 patients (average, 21.7 lymph nodes per patient). Occult tumor cells were found in 24 of 180 patients (13.3%). The presence of OLN+ was significantly associated with increased recurrence and decreased survival compared with OLN- patients (P < .001 and P = .019, respectively; relative risk of recurrence, 2.27; relative risk of death 2.07, respectively). The presence of occult lymph node metastases was an independent predictor of recurrence and death in a multivariable analysis. The outcome for patients with OLN+ disease was similar to that for patients with N+ disease.
  
  
  CONCLUSIONS
  The detection of occult lymph node metastases in patients with pT3N0 prostate cancer identifies those with significantly increased risk of prostate cancer recurrence and death.
authors.affiliation: Department of Pathology, University of Southern California, Keck School of Medicine, Los Angeles, CA 90033, USA.
authors.forename: Vincenzo
authors.initials: V
authors.lastname: Pagliarulo
authors.forename: Debra
authors.initials: D
authors.lastname: Hawes
authors.forename: Frank H
authors.initials: FH
authors.lastname: Brands
authors.forename: Susan
authors.initials: S
authors.lastname: Groshen
authors.forename: Jie
authors.initials: J
authors.lastname: Cai
authors.forename: John P
authors.initials: JP
authors.lastname: Stein
authors.forename: Gary
authors.initials: G
authors.lastname: Lieskovsky
authors.forename: Donald G
authors.initials: DG
authors.lastname: Skinner
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Cote
mesh_terms: D000368:Aged; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D009367:Neoplasm Staging; D016016:Proportional Hazards Models; D011468:Prostatectomy; D019048:Prostatic Intraepithelial Neoplasia / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D016019:Survival Analysis