title: Improvement of staging by combining tumor and treatment parameters: the value for prognostication in rectal cancer.
abstract: OBJECTIVE
  Staging of cancer is based on the TNM system. This valuable system takes only tumor-related parameters into account, but in the era of refined surgery and preoperative therapy treatment-related factors are of equal importance. By using rectal cancer as a model we explored the hypothesis that a combination of tumor- and treatment-related parameters will result in improved prognostication.
  
  
  METHODS
  Standardized clinicopathologic and histologic factors considered predictive for survival were studied in eligible patients treated in a trial for rectal cancer (n = 1324). These factors were analyzed in relation to survival using log-rank tests, Kaplan-Meier curves, and Cox regression both individually and in combination, the latter including TNM staging. A second data set from an independent trial (n = 316) was used for data validation.
  
  
  RESULTS
  Multivariate analysis identified nodal status (P = .001) and circumferential margin (P = .001) involvement as the most important prognostic factors for survival. The combination of these factors formed an improved staging system (node status and circumferential margin [NCRM]) compared with the present TNM staging with respect to 5-year cancer-specific survival. The results were confirmed in our independent patient population.
  
  
  CONCLUSIONS
  NCRM staging of rectal cancer results in a broad range of survival rates and favorable patient grouping. Our data give strong evidence that a staging system combing tumor- and treatment-related factors provides better prognostic information than the classic TNM system, which is based solely on tumor-related factors. Similar results might be obtained in other types of cancer in which quality of treatment is important for outcome.
authors.affiliation: Department of Pathology, Radboud University Medical Center, Nijmegen, The Netherlands.
authors.forename: Marleen J E M
authors.initials: MJ
authors.lastname: Gosens
authors.forename: J Han J M
authors.initials: JH
authors.lastname: van Krieken
authors.forename: Corrie A M
authors.initials: CA
authors.lastname: Marijnen
authors.forename: Elma
authors.initials: E
authors.lastname: Meershoek-Klein Kranenbarg
authors.forename: Hein
authors.initials: H
authors.lastname: Putter
authors.forename: Harm J
authors.initials: HJ
authors.lastname: Rutten
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Bujko
authors.forename: Cornelis J H
authors.initials: CJ
authors.lastname: van de Velde
authors.forename: Iris D
authors.initials: ID
authors.lastname: Nagtegaal
mesh_terms: D003082:Colectomy / Q000379:methods*; D003113:Colonoscopy; D003718:Denmark / Q000453:epidemiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009367:Neoplasm Staging / Q000379:methods*; D011379:Prognosis; D018714:Radiotherapy, Adjuvant; D012004:Rectal Neoplasms / Q000401:mortality / Q000473:pathology* / Q000628:therapy; D012720:Severity of Illness Index; D015996:Survival Rate