title: A proposal for the annotation of recurrent colorectal cancer: the 'Sheffield classification'.
abstract: OBJECTIVE
  Current classification systems of large bowel cancer only refer to metastatic disease as M0, M1 or Mx. Recurrent colorectal cancer primarily occurs in the liver, lungs, nodes or peritoneum. The management of each of these sites of recurrence has made significant advances and each is a subspecialty in its own right. The aim of this paper was to devise a classification system which accurately describes the site and extent of metastatic spread.
  
  
  METHODS
  An amendment of the current system is proposed in which liver, lung and peritoneal metastases are annotated by 'Liv 0,1', 'Pul 0,1' and 'Per 0,1' in describing the primary presentation. These are then subclassified, taking into account the chronology, size, number and geographical distribution of metastatic disease or logoregional recurrence and its K-Ras status.
  
  
  CONCLUSIONS
  This discussion document proposes a classification system which is logical and simple to use. We plan to validate it prospectively.
authors.affiliation: Liver Research Group, University of Sheffield, Sheffield, UK. a.w.majeed@sheffield.ac.uk
authors.forename: A W
authors.initials: AW
authors.lastname: Majeed
authors.forename: A J
authors.initials: AJ
authors.lastname: Shorthouse
authors.forename: A
authors.initials: A
authors.lastname: Blakeborough
authors.forename: N C
authors.initials: NC
authors.lastname: Bird
mesh_terms: D015179:Colorectal Neoplasms / Q000473:pathology*; D006801:Humans; D008113:Liver Neoplasms / Q000145:classification* / Q000473:pathology / Q000556:secondary; D008175:Lung Neoplasms / Q000145:classification* / Q000473:pathology / Q000556:secondary; D008207:Lymphatic Metastasis; D009364:Neoplasm Recurrence, Local / Q000145:classification*; D009367:Neoplasm Staging; D010534:Peritoneal Neoplasms / Q000145:classification* / Q000473:pathology / Q000556:secondary