title: Age-period-cohort analysis of colorectal cancer in East Anglia, 1971-2005.
abstract: BACKGROUND
  This study aimed to investigate the incidence trends of colorectal cancer by sex and subsite, in East Anglia from 1971 to 2005.
  
  
  METHODS
  Using data from the Eastern Cancer Registration and Information Centre, we examined the time trends and the effect of age, period of diagnosis and birth cohort on the incidence of colorectal cancer by sex and subsite.
  
  
  RESULTS
  Between 1971 and 2005, 23875 males and 22651 females were registered with colorectal cancer in East Anglia. During this period, the increase in the incidence trends was higher among males, more recent periods of diagnosis, and proximal colon. Cohort effects were statistically significant in distal and rectal cancers in males (p<0.001 and p=0.05, respectively), and in proximal colon in females (p<0.001). Period effects were statistically significant across all subsites and both sexes (p<0.001 for all).
  
  
  CONCLUSIONS
  Period effects were significant across all subsites for both sexes, whereas cohort effects varied in their significance levels depending on subsite and sex. We suggest that the period effect may be due to an increase in the use of colonoscopy for diagnostic or opportunistic screening, and the cohort effect may be due to aetiological differences in CRC between sexes and subsites.
authors.affiliation: Harvard Medical School, 260 Longwood Avenue, Boston, MA 02115, USA. jwessler@gmail.com
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Wessler
authors.forename: Nora
authors.initials: N
authors.lastname: Pashayan
authors.forename: David C
authors.initials: DC
authors.lastname: Greenberg
authors.forename: Stephen W
authors.initials: SW
authors.lastname: Duffy
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D015331:Cohort Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology*; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011159:Population Surveillance; D012737:Sex Factors; D013995:Time