title: Lymph nodes, tumor deposits, and TNM: are we getting better?
abstract: OBJECTIVE
  New editions of the TNM staging system for colorectal cancer have been subject to extensive criticism. In the current study, we evaluate each edition of TNM and analyze stage migration caused by the different versions.
  
  
  METHODS
  Two independent test populations were used: participants derived from a randomized surgical trial from the United Kingdom (n = 455) and patients from a population-based series from Sweden (n = 505). All slides from these patient cases were reviewed with special attention for the presence of tumor deposits. Tumor deposits were classified according to the fifth, sixth, and seventh editions of TNM and correlated with prognosis.
  
  
  RESULTS
  Every change in edition of TNM led to a stage migration of between 33% and 64% in patients with tumor deposits. Reproducibility was best in the fifth edition of TNM. The prognostic value of the seventh edition was best only when all tumor deposits irrespective of size or contour were included as lymph nodes. The prognostic value of the fifth edition was better than that of the sixth.
  
  
  CONCLUSIONS
  We demonstrate there is a place for tumor deposits in the staging of patients with colorectal cancer. However, many questions remain about their definition and the reproducibility and use of this category in special situations, such as after neoadjuvant treatment. These should be the subject of additional research before use as a factor in TNM staging. This work demonstrates the necessity of testing modifications before their introduction.
authors.affiliation: Department of Pathology 824, Radboud University Nijmegen Medical Center, PO Box 9101, 6500 HB, Nijmegen, The Netherlands. i.nagtegaal@pathol.umcn.nl
authors.forename: Iris D
authors.initials: ID
authors.lastname: Nagtegaal
authors.forename: Tibor
authors.initials: T
authors.lastname: Tot
authors.forename: David G
authors.initials: DG
authors.lastname: Jayne
authors.forename: Phil
authors.initials: P
authors.lastname: McShane
authors.forename: Anders
authors.initials: A
authors.lastname: Nihlberg
authors.forename: Helen C
authors.initials: HC
authors.lastname: Marshall
authors.forename: Lars
authors.initials: L
authors.lastname: Påhlman
authors.forename: Julia M
authors.initials: JM
authors.lastname: Brown
authors.forename: Pierre J
authors.initials: PJ
authors.lastname: Guillou
authors.forename: Philip
authors.initials: P
authors.lastname: Quirke
mesh_terms: D000230:Adenocarcinoma / Q000401:mortality / Q000473:pathology / Q000556:secondary*; D000368:Aged; D000369:Aged, 80 and over; D015179:Colorectal Neoplasms / Q000401:mortality / Q000473:pathology*; D018572:Disease-Free Survival; D006801:Humans; D053208:Kaplan-Meier Estimate; D008207:Lymphatic Metastasis; D008875:Middle Aged; D015337:Multicenter Studies as Topic / Q000706:statistics & numerical data; D009361:Neoplasm Invasiveness; D009367:Neoplasm Staging / Q000379:methods / Q000639:trends*; D011379:Prognosis; D016032:Randomized Controlled Trials as Topic / Q000706:statistics & numerical data; D015203:Reproducibility of Results; D013548:Sweden / Q000453:epidemiology; D047368:Tumor Burden; D006113:United Kingdom / Q000453:epidemiology