ABSTRACT
OBJECTIVE: To determine the minimum family history of colorectal cancer (CRC), which justifies colonoscopy and to establish whether further colonic assessment is necessary after a negative screening colonoscopy. METHOD: A retrospective review of every colonoscopy undertaken for family screening at the Royal Berkshire and Battle Hospitals, Reading between October 1996 and July 2004. RESULTS: Four hundred and thirty-two patients (261 women) with an average age of 48 years (range 14-84) were screened. Three cancers in patients over the age of 60 years and 49 adenomas were found in 37 patients. Twenty three of 281 (8%) patients with a 'low-risk' family history (one in 12 or less lifetime risk of developing CRC) had either a cancer or an adenoma. Eighteen of 151 (12%) patients with a 'high-risk' family history (one in 10 or greater) had a similar positive colonoscopy. Thirteen of 15 patients who had an adenoma aged under 45 years had a high-risk family history. Seventy-three patients subsequently underwent two or more follow-up colonoscopies. There were 22 adenomatous polyps found in 12 patients (16%) at the first screening, nine adenomas in seven patients in the second colonoscopy and four adenomas found in four patients in all subsequent colonoscopies. CONCLUSION: Patients with a low-risk family history have a similar adenoma pick-up to that of the general population. These patients need not be screened below the age of 50 unless symptomatic. Follow up of low-risk family history (FH) patients with a negative screening colonoscopy is unlikely to be beneficial.
