title: A nomogram for staging of exclusive nonobturator lymph node metastases in men with localized prostate cancer.
abstract: OBJECTIVE
  Some patients with localized prostate cancer are at risk of nonobturator lymph node invasion (NOLNI) and may require an extended pelvic lymph node dissection (ePLND). We explored the rate of exclusive NOLNI and developed a nomogram to predict it.
  
  
  METHODS
  We mapped all ePLND specimens according to their anatomic location (obturator, external iliac, internal iliac lymph nodes) and assessed the location-specific rate of LNI in 565 patients. A multivariate logistic regression-based nomogram predicting NOLNI was then internally validated with 200 bootstrap resamples.
  
  
  RESULTS
  Overall, 11.1% (63 of 565) had LNI and 21 (3.7%) had exclusive NOLNI. The nomogram predicting exclusive NOLNI was 80.2% accurate. The nomogram's negative predictive value was 99%, when it predicted 0-10% probability of NOLNI. This approach could allow the omission of an ePLND in 350 of 565 (61.9%) patients and still correctly stage 85.8% of NOLNI cases.
  
  
  CONCLUSIONS
  Our nomogram-based approach offers the possibility of identifying men who are at virtually zero risk of exclusive NOLNI. In these men, an ePLND may be safely avoided.
authors.affiliation: Department of Urology, Vita-Salute University, Milan, Italy.
authors.forename: Alberto
authors.initials: A
authors.lastname: Briganti
authors.forename: Felix K-H
authors.initials: FK
authors.lastname: Chun
authors.forename: Andrea
authors.initials: A
authors.lastname: Salonia
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Zanni
authors.forename: Andrea
authors.initials: A
authors.lastname: Gallina
authors.forename: Federico
authors.initials: F
authors.lastname: Dehò
authors.forename: Nazareno
authors.initials: N
authors.lastname: Suardi
authors.forename: Luigi Filippo
authors.initials: LF
authors.lastname: Da Pozzo
authors.forename: Luc
authors.initials: L
authors.lastname: Valiquette
authors.forename: Patrizio
authors.initials: P
authors.lastname: Rigatti
authors.forename: Francesco
authors.initials: F
authors.lastname: Montorsi
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D006801:Humans; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D008875:Middle Aged; D049451:Nomograms; D010388:Pelvis; D011471:Prostatic Neoplasms / Q000473:pathology*; D012307:Risk Factors