title: Continued change in the distribution of colorectal carcinoma.
abstract: BACKGROUND
  The aim of this study was to determine whether the previously reported shift in carcinoma from the left colon to the right colon has progressed.
  
  
  METHODS
  The charts of 2169 patients admitted to one institution between 1979 and 1994 with a diagnosis of colorectal carcinoma were reviewed retrospectively. The study was divided into four equal intervals. The large bowel was divided into five regions: right, transverse, left, sigmoid and rectum.
  
  
  RESULTS
  Right-sided lesions increased from 20.6 to 29.9 per cent (P = 0.001) and rectal lesions decreased from 22.0 to 11.3 per cent (P = 0.0002) from the first to the fourth study interval. The frequency of transverse, left and sigmoid colon lesions remained relatively constant.
  
  
  CONCLUSIONS
  The continuing trend of increased incidence of right-sided lesions and decreased incidence of rectal lesions was documented. Any screening examination for carcinoma requires total examination of the colon.
authors.affiliation: Department of Surgery, Sir Mortimer B. Davis Jewish General Hospital, McGill University, Montreal, Quebec, Canada.
authors.forename: D I
authors.initials: DI
authors.lastname: Obrand
authors.forename: P H
authors.initials: PH
authors.lastname: Gordon
mesh_terms: D003110:Colonic Neoplasms / Q000453:epidemiology / Q000473:pathology*; D006801:Humans; D015994:Incidence; D011792:Quebec / Q000453:epidemiology; D012004:Rectal Neoplasms / Q000453:epidemiology / Q000473:pathology*; D012189:Retrospective Studies