title: Development and external validation of a prognostic tool for prediction of cancer-specific mortality after complete loco-regional pathological staging for squamous cell carcinoma of the penis.
abstract: OBJECTIVE
  To develop a novel postoperative prognostic tool, which attempts to integrate both pathological tumour stage and histopathological factors, for prediction of cancer-specific mortality (CSM) of squamous cell carcinoma of the penis (SCCP).
  
  
  METHODS
  Patients with SCCP treated with inguinal lymph node dissection (ILND) or sentinel LN biopsy at a single institution were used for nomogram development and internal validation (n = 434), while a second cohort was used for external validation (n = 338). Multivariable Cox proportional hazards were used to examine the prognostic ability of patient age, a modified tumour staging that distinguishes between spongiosum and cavernosum body ingrowth tumours, a modified LN staging that integrates information on presence/absence of LN metastasis, extent of inguinal LN metastases, pelvic LN involvement, and extranodal involvement, and tumour grade. Model performance was quantified using measures of discrimination and calibration.
  
  
  RESULTS
  Overall, 36% of patients had positive LN metastases (n = 156). In univariable analyses, the modified tumour and LN staging systems were statistically significantly associated with CSM, and remained in the final model with a discrimination of 89% within internal validation, and 95% within external validation. Calibration was nearly perfect.
  
  
  CONCLUSIONS
  The newly developed model integrates important prognostic factors, which existing models do not consider. Its performance was highly accurate using measures of discrimination and calibration.
authors.affiliation: Department of Urology, Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Canada.
authors.forename: Maxine
authors.initials: M
authors.lastname: Sun
authors.affiliation: Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Rosa S
authors.initials: RS
authors.lastname: Djajadiningrat
authors.affiliation: Penile Cancer Centre, St George's Healthcare NHS Trust, London, UK.
authors.forename: Hussain M
authors.initials: HM
authors.lastname: Alnajjar
authors.affiliation: Department of Urology, Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Canada.
authors.forename: Quoc-Dien
authors.identifier: http://orcid.org/0000-0003-3857-9276
authors.initials: QD
authors.lastname: Trinh
authors.affiliation: Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Niels M
authors.initials: NM
authors.lastname: Graafland
authors.affiliation: Penile Cancer Centre, St George's Healthcare NHS Trust, London, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Watkin
authors.affiliation: Department of Urology, Cancer Prognostics and Health Outcomes Unit, University of Montreal Health Center, Montreal, Canada.
authors.forename: Pierre I
authors.initials: PI
authors.lastname: Karakiewicz
authors.affiliation: Department of Urology, Netherlands Cancer Institute-Antoni van Leeuwenhoek Hospital, Amsterdam, the Netherlands.
authors.forename: Simon
authors.initials: S
authors.lastname: Horenblas
mesh_terms: D002294:Carcinoma, Squamous Cell / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D006119:Groin / Q000473:pathology*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008197:Lymph Node Excision; D008207:Lymphatic Metastasis; D008297:Male; D009367:Neoplasm Staging; D049451:Nomograms; D010412:Penile Neoplasms / Q000401:mortality* / Q000473:pathology / Q000601:surgery; D010413:Penis / Q000473:pathology*; D011379:Prognosis; D011446:Prospective Studies; D015203:Reproducibility of Results
keywords: <squamous cell carcinoma of the penis; cancer-specific mortality; nomogram; prognostics