A screening clinic for relatives of patients with colorectal cancer in a district general hospital.

A family cancer screening clinic was set up to screen and counsel subjects at above average risk of developing colorectal cancer. Criteria for referral were one first degree relative under 50 years or two of any age with colorectal cancer. Pedigree information was used to estimate lifetime risks of developing colorectal cancer and offer appropriate screening: colonoscopy for high risks (greater than 1 in 10), faecal occult blood testing for lower risks. One hundred and eleven subjects from 76 families were seen over four years. Forty two families gave a pedigree consistent with dominantly inherited non-polyposis colorectal cancer syndrome (HNPCC). Three subjects from one family were found to have familial adenomatous polyposis. Ninety two colonoscopies yielded 21 patients with polyps (12 had tubular adenomas, including one with early malignant invasion). Thirty three per cent (four of 12) of the tubular adenomas were beyond the reach of a flexible sigmoidoscope. Three hundred and forty two further high risk relatives were identified from the family history.