title: Relationship between lymph node ratio and cancer-specific survival in a contemporary series of patients with penile cancer and lymph node metastases.
abstract: OBJECTIVE
  To evaluate the association between lymph node ratio (LNR) and cancer-specific survival (CSS) in a population of patients with penile cancer and lymph node metastases (LNM).
  
  
  METHODS
  We evaluated 81 patients with pathologically determined LNM who were surgically treated at our institution between 2000 and 2012. We considered LNR both as a continuously coded and as a categorically coded variable. The minimum-P-value approach was used to determine the most significant LNR threshold. The Kaplan-Meier method was used to determine CSS rates, and univariable and multivariable Cox regression models were fitted to test the predictors of CSS.
  
  
  RESULTS
  The median (interquartile range [IQR]) numbers of positive and removed lymph nodes were 2 (1-4) and 22 (13-30), respectively. The median (IQR) LNR was 10.3 (6.3-16.6)% and the most significant LNR threshold was 22%. The median (IQR) follow-up was 26 (16-62) months. Overall, the 5-year CSS rate was 50.5%. After stratification according to LNR, 5-year CSS rates were 65.2% vs 9.6% in patients with LNR < 22% vs LNR ≥ 22%, respectively (P < 0.001). In multivariable Cox regression models, after adjusting for several established prognostic factors, LNR was as independent predictor of CSS (P≤0.012). Finally, LNR significantly improved the accuracy of multivariable Cox regression models by 4.9-10.5%.
  
  
  CONCLUSIONS
  Although further investigations are needed to evaluate the relationship between tumour burden and treatment intensity, LNR may represent a powerful predictor of CSS in patients with penile cancer and pathologically determined LNM.
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.|Department of Urology, San Raffaele Turro, Fondazione IRCCS Ospedale San Raffaele, Milan, Italy.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Lughezzani
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Mario
authors.initials: M
authors.lastname: Catanzaro
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Tullio
authors.initials: T
authors.lastname: Torelli
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Luigi
authors.initials: L
authors.lastname: Piva
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Biasoni
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Silvia
authors.initials: S
authors.lastname: Stagni
authors.affiliation: Department of Oncology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Andrea
authors.initials: A
authors.lastname: Necchi
authors.affiliation: Department of Oncology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Patrizia
authors.initials: P
authors.lastname: Giannatempo
authors.affiliation: Department of Oncology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Daniele
authors.initials: D
authors.lastname: Raggi
authors.affiliation: Department of Oncology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Elena
authors.initials: E
authors.lastname: Fare'
authors.affiliation: Department of Pathology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Maurizio
authors.initials: M
authors.lastname: Colecchia
authors.affiliation: Department of Pathology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Pizzocaro
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Salvioni
authors.affiliation: Department of Urology, Fondazione IRCCS Istituto Nazionale Tumori, Milan, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Nicolai
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008198:Lymph Nodes / Q000473:pathology*; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D010412:Penile Neoplasms / Q000401:mortality / Q000473:pathology* / Q000601:surgery; D011237:Predictive Value of Tests; D011379:Prognosis
keywords: cancer-specific survival; lymph node ratio; lymph nodes; pN stage; penile cancer; prognosis