Prevalence of family history of colorectal cancer in the general population.
BACKGROUND
Robust estimates of the prevalence of a family history of colorectal cancer in the general population are essential to inform planning of provision for colonoscopic surveillance and for clinical genetics services. However, there is a paucity of high-quality data.


METHODS
Computerized record linkage was used to assess systematically the family history of 160 cancer-free community subjects and thereby provide prevalence data that are independent of participant recall. The data set comprised 2664 first- and second-degree relatives of study subjects, with 148 068 years at risk.


RESULTS
Of people in the 30-70 years age range, 9.4 (95 per cent confidence interval (c.i.) 5.8 to 14.9) per cent had a first-degree relative affected by colorectal cancer, and 28.8 (95 per cent c.i. 22.3 to 36.2) per cent had an affected first- or second-degree relative. Between 0 and 3.1 per cent of study subjects merited colonic surveillance, depending on the stringency of the guidelines used.


CONCLUSIONS
An appreciable proportion of the general population has a relative affected by colorectal cancer, sufficient to merit screening under certain criteria. In the absence of good-quality evidence supporting colonoscopic surveillance in groups at moderate risk, these data directly inform the planning of services for people with a family history of colorectal cancer. However, the clinical risk and financial implications of screening should be taken into account.
Colon Cancer Genetics Group, University of Edinburgh, Division of Clinical and Molecular Medicine and Medical Research Council Human Genetics Unit, Western General Hospital, Edinburgh, UK.
R J
RJ
Mitchell
H
H
Campbell
S M
SM
Farrington
D H
DH
Brewster
M E M
ME
Porteous
M G
MG
Dunlop
D000328:Adult; D000368:Aged; D016022:Case-Control Studies; D015179:Colorectal Neoplasms / Q000453:epidemiology / Q000235:genetics*; D016001:Confidence Intervals; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010375:Pedigree; D015995:Prevalence; D012606:Scotland / Q000453:epidemiology