title: Change in anatomic distribution and incidence of colorectal carcinoma over a period of 15 years: clinical considerations.
abstract: OBJECTIVE
  Colorectal cancer is the second most common cancer in the Netherlands. Its incidence rates are among the highest in Europe. In the past decades, a right-sided shift of the subsite location of colorectal cancer has been reported. These changes in anatomic distribution might have clinical implications for the use of diagnostic or screening tools for colorectal cancer. This study was designed to investigate the change in incidence and anatomic distribution of colorectal cancer in a population over a period of 15 years.
  
  
  METHODS
  The incidence of colorectal cancer in an eastern part of the Netherlands (700,000 inhabitants) was determined for two years, 1981 and 1996. From the regional laboratory of pathology, data including age, gender, subsite location, and Dukes classification were collected. The subsite location of colorectal cancer was divided into two groups: proximal and distal (the latter being within sigmoidoscopy reach).
  
  
  RESULTS
  No differences in age and gender distribution were found. In 1981, the diagnosis of colorectal cancer was made in 232 patients in this region, and in 1996, it was made in 410 patients. The population remained almost stable during this time. Therefore, the incidence rose from 33 to 55 per 100,000 inhabitants from 1981 to 1996, respectively. In 1981, 25 percent of the carcinomas were proximal (to the sigmoid colon); this increased to 37 percent in 1996 ( P< 0.05).
  
  
  CONCLUSIONS
  The incidence of colorectal cancer has almost doubled from 1981 to 1996 in this Dutch region. The proportion of proximal colorectal cancer has increased from 25 to 37 percent. These findings add to the notion that sigmoidoscopy is not the optimal diagnostic or screening tool for colorectal cancer.
authors.affiliation: Department of Internal Medicine and Gastroenterology, Medisch Spectrum Twente, Enschede, the Netherlands.
authors.forename: P B F
authors.initials: PB
authors.lastname: Mensink
authors.forename: J J
authors.initials: JJ
authors.lastname: Kolkman
authors.forename: J
authors.initials: J
authors.lastname: Van Baarlen
authors.forename: J H
authors.initials: JH
authors.lastname: Kleibeuker
mesh_terms: D000368:Aged; D015179:Colorectal Neoplasms / Q000175:diagnosis / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D009426:Netherlands / Q000453:epidemiology; D012189:Retrospective Studies; D012812:Sigmoidoscopy