title: Incidence of hereditary non-polyposis colorectal cancer in a population-based study of 1137 consecutive cases of colorectal cancer.
abstract: BACKGROUND
  Previous reports have indicated that 5-13 per cent of colorectal cancer is hereditary. However, the proportion of cases arising as a result of mutations in the hereditary non-polyposis colorectal cancer (HNPCC) genes remains to be determined.
  
  
  METHODS
  This study is a part prospective, part retrospective review of all cases of colorectal cancer from a district hospital over 14 years. Some 1137 consecutive patients with colorectal cancer were questioned about their family history of cancer and details were logged on a database. For the past 4 years each case has been re-evaluated where possible.
  
  
  RESULTS
  Some 118 patients indicated initially that they had a first-degree relative with colorectal cancer, but on re-evaluation there were significant discrepancies. Only three cases (0.3 per cent) occurred in families which strictly fulfilled the criteria for HNPCC and there were no cases of familial adenomatous polyposis. A total of 16 patients (1.4 per cent) fulfilled looser criteria for HNPCC.
  
  
  CONCLUSIONS
  This population-based study has shown a lower frequency of familial bowel cancer than previous studies and may reflect a lower incidence of inherited mutations in the HNPCC DNA mismatch repair genes than is currently accepted.
authors.affiliation: Department of Medical Genetics, St Mary's Hospital, Manchester, UK.
authors.forename: D G
authors.initials: DG
authors.lastname: Evans
authors.forename: S
authors.initials: S
authors.lastname: Walsh
authors.forename: J
authors.initials: J
authors.lastname: Jeacock
authors.forename: C
authors.initials: C
authors.lastname: Robinson
authors.forename: L
authors.initials: L
authors.lastname: Hadfield
authors.forename: D R
authors.initials: DR
authors.lastname: Davies
authors.forename: R
authors.initials: R
authors.lastname: Kingston
mesh_terms: D000328:Adult; D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D003123:Colorectal Neoplasms, Hereditary Nonpolyposis / Q000453:epidemiology*; D004198:Disease Susceptibility; D004739:England / Q000453:epidemiology; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D011446:Prospective Studies; D012189:Retrospective Studies